HollowLord Profile Joined August 2010 United States 136 Posts #1 Warning: This is a very long and very boring analysis of MMR distribution. If you are not interested, by all means skip it by. I sure as hell wouldn't have read through the entire thing if I hadn't been the one to write it.



To begin, I'd like to address exactly what MMR is. Everyone is familiar with that little number next to each game that constantly reminds you of your success or failure, but what exactly does that number represent? Valve has been frustratingly quiet on exactly how the system works, but ever since the advent of Ranked Matchmaking it has become a bit more clear. One of the earlier theories of Valve's matchmaking was that it was based on a



However, last year Valve released a is a number associated with your ranking. More importantly, Valve talks about a 'calibration process' in which players who are new to the game go through levels of uncertainty before being assigned their rating. This is, at first glance at least, an implementation of a



The system is inflationary. Systems like this will, either quickly or slowly, rise in average value over time. The best example of this can be found in rating systems for the Japanese game of Go. Simply put, new or inexperienced players will bring more points into the system, exchange them with others and, on average, stop playing the game with less points than they started with.



The system is based on probability. Points are awarded or taken away from wins or losses based on each team's perceived chances of winning against the enemy team. Yes, you were all waiting for it, but Dota 2 is in fact a team game. If you are solo queuing in a team game, your MMR will not be a perfect representation of your skill. This is the argument normally used by people who believe in 'Elo Hell'(League of Legends) or 'The Trench'(Dota 2). Other players either on your team or the enemy's will skew the normal perception of odds. Even in a one on one scenario, your MMR is based on probability. What is the probability of you winning, what is the probability of you losing? The number finally associated with your skill level is your probable rating.



The system gets more accurate the more you play. This fact is often overlooked, but is without a doubt the most important feature of a system of this nature. The system will never be perfectly accurate, but the more that you play the more accurate it will become. And this isn't something that happens over ten games, or twenty, or a hundred. In order to achieve a more accurate rating one would need to play thousands of games.





So, after all these words that I wrote, we can finally come at a general definition of MMR. MMR is an attempted representation of any one individual's relative skill at the game. No, this is nothing revolutionary, everybody knows this. But the most important word in that definition is 'relative'. MMR is not a representation of your skill level, it is a representation of your relative skill level. MMR does not tell you if you are good or bad at the game, it tells you if you are better or worse than the person next to you.



So where do Regions fit in? Well, recall that MMR is a relative measure of skill and not an actual marker of ability. MMR is not a stat, the kind like Strength or Dexterity found in RPGs, higher is not necessarily better.



Let's suppose there are two different communities of Dota 2 players that have never heard of one another. Each community has some hundred members that play only against members of their own community. For the purpose of this discussion we can call the first community 'Guinland' and the second community 'Frogville'.



In Guinland and Frogville, every player starts with 500 MMR, and over two or three years there is eventually a spread amongst players. The majority of players remain at around the 500 level, while the particularly poorly skilled or inexperienced players drop down to 400, 300, or in extreme cases even 200 or 100. Meanwhile, certain players demonstrate skill and talent in the game and manage to climb up to levels of 600, 700, or even possibly 800 and 900. We are left with a standard bell curve not just of players from one community, but of all Dota players. It is at this point that we can look at the distribution of MMR and say "The average player is 500 MMR. If you are 600, you are above average. If you are 400, you are below average."



So, while the residents of Guinland happily enjoy their standard spread and various players rise and fall, a curious incident happens in Frogville. Twenty new citizens arrive and, upon looking at the game decide "We want to play too!" Well, there's no problem here. Each new player is given 500 MMR and thrown into the fray. Some win, some lose, some excel, but some actually stop playing the game altogether. "Maybe it's not for me" they decide, after getting crushed ten games in a row and dropping to 300 MMR. Well the player who entered the scene with 500 MMR and left with 300 MMR now has 200 points floating in the system. Over time, the points are spread across the rest of the population and the average MMR goes up. "500 MMR? Hah, that's terrible now, you're nobody unless you have at least 600!"



Meanwhile, back in Guinland, a different sort of phenomenon makes itself apparent. One player has shown himself to be so talented, so dominant, and so unstoppable at the game that nobody can beat him. He wins constantly, and gathers more and more MMR for himself. With the hundred players in Guinland each starting at 500 MMR, that leaves a grand total of 50,000 points. Each player controls 1% of the points. But with this new player so unstoppable, he manages to accumulate 5000 points, giving him 10% of the pool and leaving less points to go around. On average, every player other than him goes down. "The average player? Oh, I would say they are around 400!"



On their own, neither of these scenarios pose any problems. The average MMR for Guinland becomes 400 while the average MMR for Frogville becomes 600. All of a sudden however, Guinland and Frogville become aware of one another. Even more than that, a small option becomes available in their game client. "Would you like to queue for servers in Guinland, Frogville, or both?" The vast majority of players aren't interested in the other region. Not only do they speak a different language, but there will be more latency. Some players, however, opt for a different server. Maybe a player in Guinland has friends in Frogville, or maybe a player in Frogville just wants shorter queue times. We now have a very serious problem.



Take your average player from Guinland. This player sits comfortable at 400 MMR, but has decided to find a game in Frogville. In Frogville of course, 400 MMR is a bit below average. Remember that MMR is a representation of relative skill. It is not used to determine if you belong with good players or bad players, it is used to associate you with other players at the same ranking as yourself. And so the matchmaking system registers this player: "Right this way Mister 400, we have a group of nine other 400 level players waiting and ready to go!" The system itself has absolutely no idea whether a 400 level player has competent rune control, good map awareness, or fast reaction speed. The player from Guinland is certainly not a newcomer, he has hundreds of games under his belt and is well past the point of calibration. So the system naturally associates him others at his level of MMR. Here we have a player of average skill competing in a game against people who are not as good as him. The odds are in his favor and, if we recall, the MMR system is based on probability. This game, that of two teams each with 400 MMR, is calculated as being an even game. That is to say, there should be a 50% chance of victory for either team. This is however, clearly not the case. To pull numbers out of a hat, we could say that one team has a 60% chance of winning, despite being calculated as having a 50% chance of winning. The Matchmaking System has not accounted for the skill discrepancy because it perceives the game as being even. But the game is not even, and when one side has an unaccounted advantage over another, the system falls apart.



So let's put aside the silly analogies for a second and talk about what is really going on. Unfortunately, I have very little actual statistics I can discuss. Valve has kept information about MMR distribution or matchmaking formulas under lock and key, so what little I have to go on comes from people who have scraped the API, as well as generalizations that are taken as presumptions for the basis of argument.



What can we conclude from this silly little thought experiment? It's entirely possible that the variance discussed accounts for a fraction of a fraction of a percentage of MMR distribution. One thing that I believe however is clearly evident is that MMR averages are not evenly distributed among regions, and I believe that anyone who has spent a prolonged time playing multiple games on more than one server will tell you that the shift between them can be very peculiar at times. The European servers in particular are believed to have a much higher average MMR value than others due to a surge of Account Boosting. The North American servers are also typically perceived as having a lower average MMR, sometimes attributed to the much smaller Professional scene in North America. If there are 100 people with 7000 mmr, 49 in China, 49 in Europe, and 2 in North America, that means there's less of an overall MMR pool in the North American servers, and those who do excel have less competition. A player in New York and a player in Sweden can be identical in skill level, but have drastically different MMR.



So what do you think? Is it a problem, am I over-reacting? Am I wrong, am I right? I genuinely want to open this to discussion, because I feel like it's a topic that has somehow been overlooked. To begin, I'd like to address exactly what MMR is. Everyone is familiar with that little number next to each game that constantly reminds you of your success or failure, but what exactly does that number represent? Valve has been frustratingly quiet on exactly how the system works, but ever since the advent of Ranked Matchmaking it has become a bit more clear. One of the earlier theories of Valve's matchmaking was that it was based on a Bayesian system which used pattern recognition in your play to assign you with players in similar categories. This is the type of system used by applications like G-Mail to determine whether an incoming mail is a message, a promotion, a social media notification, spam, etc.However, last year Valve released a blog post announcing Ranked MMR and bringing to light a few mysteries. For starters, therea number associated with your ranking. More importantly, Valve talks about a 'calibration process' in which players who are new to the game go through levels of uncertainty before being assigned their rating. This is, at first glance at least, an implementation of a Glicko matchmaking system which would explain the rumored Smurf Detection. Whether there is or is not actual Smurf Detection is unclear, but if there is then it would be thanks to a system of this nature. So Valve uses some formula, whatever it may be, that builds on the Glicko rating system and ultimately has its roots in the (now infamous in online gaming) Elo rating, modified with various criteria. We can draw a few conclusions about matchmaking in general from this:So, after all these words that I wrote, we can finally come at a general definition of MMR.No, this is nothing revolutionary, everybody knows this. But the most important word in that definition isMMR does not tell you if you areorat the game, it tells you if you areorthan the person next to you.So where do Regions fit in? Well, recall that MMR is a relative measure of skill and not an actual marker of ability. MMR is not a stat, the kind like Strength or Dexterity found in RPGs, higher is not necessarily better.Let's suppose there are two different communities of Dota 2 players that have never heard of one another. Each community has some hundred members that play only against members of their own community. For the purpose of this discussion we can call the first community 'Guinland' and the second community 'Frogville'.In Guinland and Frogville, every player starts with 500 MMR, and over two or three years there is eventually a spread amongst players. The majority of players remain at around the 500 level, while the particularly poorly skilled or inexperienced players drop down to 400, 300, or in extreme cases even 200 or 100. Meanwhile, certain players demonstrate skill and talent in the game and manage to climb up to levels of 600, 700, or even possibly 800 and 900. We are left with a standard bell curve not just of players from one community, but of all Dota players. It is at this point that we can look at the distribution of MMR and saySo, while the residents of Guinland happily enjoy their standard spread and various players rise and fall, a curious incident happens in Frogville. Twenty new citizens arrive and, upon looking at the game decide "We want to play too!" Well, there's no problem here. Each new player is given 500 MMR and thrown into the fray. Some win, some lose, some excel, but some actually stop playing the game altogether. "Maybe it's not for me" they decide, after getting crushed ten games in a row and dropping to 300 MMR. Well the player who entered the scene with 500 MMR and left with 300 MMR now has 200 points floating in the system. Over time, the points are spread across the rest of the population and the average MMR goes up.Meanwhile, back in Guinland, a different sort of phenomenon makes itself apparent. One player has shown himself to be so talented, so dominant, and so unstoppable at the game that nobody can beat him. He wins constantly, and gathers more and more MMR for himself. With the hundred players in Guinland each starting at 500 MMR, that leaves a grand total of 50,000 points. Each player controls 1% of the points. But with this new player so unstoppable, he manages to accumulate 5000 points, giving him 10% of the pool and leaving less points to go around. On average, every player other than him goes down.On their own, neither of these scenarios pose any problems. The average MMR for Guinland becomes 400 while the average MMR for Frogville becomes 600. All of a sudden however, Guinland and Frogville become aware of one another. Even more than that, a small option becomes available in their game client.The vast majority of players aren't interested in the other region. Not only do they speak a different language, but there will be more latency. Some players, however, opt for a different server. Maybe a player in Guinland has friends in Frogville, or maybe a player in Frogville just wants shorter queue times.Take your average player from Guinland. This player sits comfortable at 400 MMR, but has decided to find a game in Frogville. In Frogville of course, 400 MMR is a bit below average.And so the matchmaking system registers this player:The system itself has absolutely no idea whether a 400 level player has competent rune control, good map awareness, or fast reaction speed. The player from Guinland is certainly not a newcomer, he has hundreds of games under his belt and is well past the point of calibration. So the system naturally associates him others at his level of MMR. Here we have a player of average skill competing in a game against people who are not as good as him. The odds are in his favor and, if we recall,This game, that of two teams each with 400 MMR, is calculated as being an even game. That is to say, therebe a 50% chance of victory for either team. This is however, clearly not the case. To pull numbers out of a hat, we could say that one team has a 60% chance of winning, despite being calculated as having a 50% chance of winning.But the game is not even, and when one side has anadvantage over another,So let's put aside the silly analogies for a second and talk about what is really going on. Unfortunately, I have very little actual statistics I can discuss. Valve has kept information about MMR distribution or matchmaking formulas under lock and key, so what little I have to go on comes from people who have scraped the API, as well as generalizations that are taken as presumptions for the basis of argument.What can we conclude from this silly little thought experiment? It's entirely possible that the variance discussed accounts for a fraction of a fraction of a percentage of MMR distribution. One thing that I believe however is clearly evident is that MMR averages areevenly distributed among regions, and I believe that anyone who has spent a prolonged time playing multiple games on more than one server will tell you that the shift between them can be very peculiar at times. The European servers in particular are believed to have a much higher average MMR value than others due to a surge of Account Boosting. The North American servers are also typically perceived as having a lower average MMR, sometimes attributed to the much smaller Professional scene in North America. If there are 100 people with 7000 mmr, 49 in China, 49 in Europe, and 2 in North America, that means there's less of an overall MMR pool in the North American servers, and those who do excel have less competition.So what do you think? Is it a problem, am I over-reacting? Am I wrong, am I right? I genuinely want to open this to discussion, because I feel like it's a topic that has somehow been overlooked. dota 2 stream #noskill #feed #noob twitch.tv/dmcredgrave

TheYango Profile Joined September 2008 United States 10886 Posts Last Edited: 2014-09-17 18:37:42 #2 The system is inflationary. Systems like this will, either quickly or slowly, rise in average value over time. The best example of this can be found in rating systems for the Japanese game of Go. Simply put, new or inexperienced players will bring more points into the system, exchange them with others and, on average, stop playing the game with less points than they started with.



You overestimate the influence of this component. Your initial ranked rating being based on your non-ranked MMR does 2 things:



1) The number of "new players that leave the system with less rating than they started" is drastically reduced because most of the players that leave that way won't get to playing ranked in the first place given the games played requirement for starting ranked in the first place



2) The number of points pushed/pulled from the system by a new player is sharply reduced when they come into the system with their non-ranked MMR. In fact, if we believe their non-ranked MMR equally over- and under-estimates players' MMR, then the amount of points given/taken away by new players will cancel out over time.



Note that this is DIFFERENT from other Elo-based systems that give new players a fixed starting Elo, which causes them to give/take points from the system as the system has to correct for the discrepancy between the initial rating and their actual rating. Rather, DotA 2 putting new players in at their estimated MMR based on their non-ranked games attempts to minimize this discrepancy. You overestimate the influence of this component. Your initial ranked rating being based on your non-ranked MMR does 2 things:1) The number of "new players that leave the system with less rating than they started" is drastically reduced because most of the players that leave that way won't get to playing ranked in the first place given the games played requirement for starting ranked in the first place2) The number of points pushed/pulled from the system by a new player is sharply reduced when they come into the system with their non-ranked MMR. In fact, if we believe their non-ranked MMR equally over- and under-estimates players' MMR, then the amount of points given/taken away by new players will cancel out over time.Note that this is DIFFERENT from other Elo-based systems that give new players a fixed starting Elo, which causes them to give/take points from the system as the system has to correct for the discrepancy between the initial rating and their actual rating. Rather, DotA 2 putting new players in at their estimated MMR based on their non-ranked games attempts to minimize this discrepancy. Moderator

Furikawari Profile Joined February 2014 France 2149 Posts #3 I'm a go player and I really dont understand your point about go rating system... Traditional one is based on evaluation, automatic one are more like ELO systems.

HollowLord Profile Joined August 2010 United States 136 Posts Last Edited: 2014-09-17 18:45:53 #4 On September 18 2014 03:35 TheYango wrote:

You overestimate the influence of this component. Your initial ranked rating being based on your non-ranked MMR does 2 things:



1) The number of "new players that leave the system with less rating than they started" is drastically reduced because most of the players that leave that way won't get to playing ranked in the first place given the games played requirement for starting ranked in the first place



2) The number of points pushed/pulled from the system by a new player is sharply reduced when they come into the system with their non-ranked MMR. In fact, if we believe their non-ranked MMR equally over- and under-estimates players' MMR, then the amount of points given/taken away by new players will cancel out over time.



Note that this is DIFFERENT from other Elo-based systems that give new players a fixed starting Elo, which causes them to give/take points from the system as the system has to correct for the discrepancy between the initial rating and their actual rating. Rather, DotA 2 putting new players in at their estimated MMR based on their non-ranked games attempts to minimize this discrepancy.



This is a very good point and it's one that I didn't take into consideration; it is true that the Unranked MMR value adds a spin to it, but do you really believe that there won't be inflation because of it? When you consider that, on average, higher MMR players tend to play more games than lower MMR players, I infer from that that a below-average player is more likely to leave the game than an above-average player.



This is a very good point and it's one that I didn't take into consideration; it is true that the Unranked MMR value adds a spin to it, but do you really believe that there won't be inflation because of it? When you consider that, on average, higher MMR players tend to play more games than lower MMR players, I infer from that that a below-average player is more likely to leave the game than an above-average player. On September 18 2014 03:38 Furikawari wrote:

I'm a go player and I really dont understand your point about go rating system... Traditional one is based on evaluation, automatic one are more like ELO systems.



I was referring specifically to the formulas used by the EGF. I was referring specifically to the formulas used by the EGF. dota 2 stream #noskill #feed #noob twitch.tv/dmcredgrave

HollowLord Profile Joined August 2010 United States 136 Posts Last Edited: 2014-09-17 18:45:31 #5 Quote is not edit. dota 2 stream #noskill #feed #noob twitch.tv/dmcredgrave

TheYango Profile Joined September 2008 United States 10886 Posts #6 On September 18 2014 03:40 HollowLord wrote:

This is a very good point and it's one that I didn't take into consideration; it is true that the Unranked MMR value adds a spin to it, but do you really believe that there won't be inflation because of it? When you consider that, on average, higher MMR players tend to play more games than lower MMR players, I infer from that that a below-average player is more likely to leave the game than an above-average player.



I don't disagree with that. However, it is NOT a given that he leaves the system with less points than he started. If he's below average, his normal MMR already represents that, so it's not guaranteed that all such players will enter ranked and lose rating. I don't disagree with that. However, it is NOT a given that he leaves the system with less points than he started. If he's below average, his normal MMR already represents that, so it's not guaranteed that all such players will enter ranked and lose rating. Moderator

FHDH Profile Joined July 2014 United States 7023 Posts #7 ELO-like systems work as sorting mechanisms that are self-correcting over time. In your scenario where all players have the same MMR, the system says there is a 50% chance you will win if this is your correct MMR, and it will award/deduct equal points on outcome based on this assumption.



If it is your correct MMR, then over a sufficient period of time you are likely to see no relative change in MMR as you will find equilibrium at the same relative MMR (accounting for inflationary forces, this may go up over time). However, if a player on a team is good enough that he creates a 60% chance of winning, the way this is accounted for is iteratively: he will be gradually sorted into higher brackets until equilibrium is found. If he were then to play in that same group the points would reflect a different expected outcome. As for the rest of the players, if their MMR reflected their true skill, the winners would be forced back down and the losers would be forced back up.



ELO systems basically say "are you as good as your MMR says you are?" If you are not, your score will drop. If you are better, your score will rise. But only over time, and only through many iterations that cancel out fairly random elements. После драки кулаками не машут (Don't shake your fist when the fight is over)

Andre Profile Joined August 2009 Slovenia 1441 Posts #8 There's already inflation, just check the leaderboards. It's partially the fault of account sellers though, a lot of people who buy 7k++ accounts and then spread the rating around.



Like when leaderboards initially came out, first month the top players were around 5.6k-5.7k rating, now they're 7k ++. To enter the top200 you had to have around 5400 rating now you need 6k. You must gather your party before venturing forth.

HollowLord Profile Joined August 2010 United States 136 Posts Last Edited: 2014-09-17 18:52:02 #9 On September 18 2014 03:47 TheYango wrote:

Show nested quote +

On September 18 2014 03:40 HollowLord wrote:

This is a very good point and it's one that I didn't take into consideration; it is true that the Unranked MMR value adds a spin to it, but do you really believe that there won't be inflation because of it? When you consider that, on average, higher MMR players tend to play more games than lower MMR players, I infer from that that a below-average player is more likely to leave the game than an above-average player.



I don't disagree with that. However, it is NOT a given that he leaves the system with less points than he started. If he's below average, his normal MMR already represents that, so it's not guaranteed that all such players will enter ranked and lose rating. I don't disagree with that. However, it is NOT a given that he leaves the system with less points than he started. If he's below average, his normal MMR already represents that, so it's not guaranteed that all such players will enter ranked and lose rating.



However say that two players start at the same time, one of which is skilled and the other one not so much. The skilled player will advance towards Ranked while taking wins from the lesser skilled player, who ends up quitting before he even gets there. This means that someone with an above average MMR is more likely to enter the system than someone with a below average MMR. Even if it's by a fraction of a percentage, it adds up eventually. However say that two players start at the same time, one of which is skilled and the other one not so much. The skilled player will advance towards Ranked while taking wins from the lesser skilled player, who ends up quitting before he even gets there. This means that someone with an above average MMR is more likely to enter the system than someone with a below average MMR. Even if it's by a fraction of a percentage, it adds up eventually. dota 2 stream #noskill #feed #noob twitch.tv/dmcredgrave

HollowLord Profile Joined August 2010 United States 136 Posts Last Edited: 2014-09-17 18:56:43 #10 On September 18 2014 03:48 FHDH wrote:

ELO systems basically say "are you as good as your MMR says you are?" If you are not, your score will drop. If you are better, your score will rise. But only over time, and only through many iterations that cancel out fairly random elements.



I disagree. Elo systems do not say "Are you as good as your MMR says you are?" Elo systems say "Are you as good as the other people at your MMR?" If you are, your MMR will rise, if you are not, your MMR will drop. I disagree. Elo systems do not say "Are you as good as your MMR says you are?" Elo systems say "Are you as good as the other people at your MMR?" If you are, your MMR will rise, if you are not, your MMR will drop. dota 2 stream #noskill #feed #noob twitch.tv/dmcredgrave

FHDH Profile Joined July 2014 United States 7023 Posts #11 On September 18 2014 03:53 HollowLord wrote:

Show nested quote +

On September 18 2014 03:48 FHDH wrote:

ELO systems basically say "are you as good as your MMR says you are?" If you are not, your score will drop. If you are better, your score will rise. But only over time, and only through many iterations that cancel out fairly random elements.



I disagree. Elo systems do not say "Are you as good as your MMR says you are?" Elo systems say "Are you as good as the other people at your MMR?" If you are, your MMR will rise, if you are not, your MMR will drop. I disagree. Elo systems do not say "Are you as good as your MMR says you are?" Elo systems say "Are you as good as the other people at your MMR?" If you are, your MMR will rise, if you are not, your MMR will drop.

Literally saying the same thing, only comparing it to the one place I didn't mention the relative aspect. Literally saying the same thing, only comparing it to the one place I didn't mention the relative aspect. После драки кулаками не машут (Don't shake your fist when the fight is over)

TheYango Profile Joined September 2008 United States 10886 Posts #12 On September 18 2014 03:51 HollowLord wrote:

Show nested quote +

On September 18 2014 03:47 TheYango wrote:

On September 18 2014 03:40 HollowLord wrote:

This is a very good point and it's one that I didn't take into consideration; it is true that the Unranked MMR value adds a spin to it, but do you really believe that there won't be inflation because of it? When you consider that, on average, higher MMR players tend to play more games than lower MMR players, I infer from that that a below-average player is more likely to leave the game than an above-average player.



I don't disagree with that. However, it is NOT a given that he leaves the system with less points than he started. If he's below average, his normal MMR already represents that, so it's not guaranteed that all such players will enter ranked and lose rating. I don't disagree with that. However, it is NOT a given that he leaves the system with less points than he started. If he's below average, his normal MMR already represents that, so it's not guaranteed that all such players will enter ranked and lose rating.



However say that two players start at the same time, one of which is skilled and the other one not so much. The skilled player will advance towards Ranked while taking wins from the lesser skilled player, who ends up quitting before he even gets there. This means that someone with an above average MMR is more likely to enter the system than someone with a below average MMR. Even if it's by a fraction of a percentage, it adds up eventually. However say that two players start at the same time, one of which is skilled and the other one not so much. The skilled player will advance towards Ranked while taking wins from the lesser skilled player, who ends up quitting before he even gets there. This means that someone with an above average MMR is more likely to enter the system than someone with a below average MMR. Even if it's by a fraction of a percentage, it adds up eventually.

But because the normal and ranked MMR pools are kept separate, the below-average player leaving doesn't alter the ranked pool of MMR. He affects the normal pool, but that doesn't matter. Particularly if we consider that a person's normal MMR ceases to influence their ranked MMR the moment they play their first ranked game, the over-time inflation of the normal MMR pool has no bearing toward inflating ranked MMR. But because the normal and ranked MMR pools are kept separate, the below-average player leaving doesn't alter the ranked pool of MMR. He affects the normal pool, but that doesn't matter. Particularly if we consider that a person's normal MMR ceases to influence their ranked MMR the moment they play their first ranked game, the over-time inflation of the normal MMR pool has no bearing toward inflating ranked MMR. Moderator

Kuroeeah Profile Joined February 2013 7937 Posts #13 [Side Tangent]

I do believe there's a problem with the system that's effecting the players with really high MMR (the 6k to 7k bracket) and many pro players expressed the same.



A 6k rated player's game typically looks like this :

(1 6k rated player + 4 other 4k rated players) vs (a group of evenly distributed lower 5k rated players).



I get why the algorithm behaves this way (both team's total accumulative MMR will match each other) but this compromises the quality of games and sounds like a total nightmare. It becomes less about two evenly matched teams playing off against each other and more about how hard one dude can carry his team.



I'm sure it comes at the expense of having to wait forever in a queue time to get an even MMR distribution within a team.

HollowLord Profile Joined August 2010 United States 136 Posts #14 On September 18 2014 04:20 TheYango wrote:

Show nested quote +

On September 18 2014 03:51 HollowLord wrote:

On September 18 2014 03:47 TheYango wrote:

On September 18 2014 03:40 HollowLord wrote:

This is a very good point and it's one that I didn't take into consideration; it is true that the Unranked MMR value adds a spin to it, but do you really believe that there won't be inflation because of it? When you consider that, on average, higher MMR players tend to play more games than lower MMR players, I infer from that that a below-average player is more likely to leave the game than an above-average player.



I don't disagree with that. However, it is NOT a given that he leaves the system with less points than he started. If he's below average, his normal MMR already represents that, so it's not guaranteed that all such players will enter ranked and lose rating. I don't disagree with that. However, it is NOT a given that he leaves the system with less points than he started. If he's below average, his normal MMR already represents that, so it's not guaranteed that all such players will enter ranked and lose rating.



However say that two players start at the same time, one of which is skilled and the other one not so much. The skilled player will advance towards Ranked while taking wins from the lesser skilled player, who ends up quitting before he even gets there. This means that someone with an above average MMR is more likely to enter the system than someone with a below average MMR. Even if it's by a fraction of a percentage, it adds up eventually. However say that two players start at the same time, one of which is skilled and the other one not so much. The skilled player will advance towards Ranked while taking wins from the lesser skilled player, who ends up quitting before he even gets there. This means that someone with an above average MMR is more likely to enter the system than someone with a below average MMR. Even if it's by a fraction of a percentage, it adds up eventually.

But because the normal and ranked MMR pools are kept separate, the below-average player leaving doesn't alter the ranked pool of MMR. He affects the normal pool, but that doesn't matter. Particularly if we consider that a person's normal MMR ceases to influence their ranked MMR the moment they play their first ranked game, the over-time inflation of the normal MMR pool has no bearing toward inflating ranked MMR. But because the normal and ranked MMR pools are kept separate, the below-average player leaving doesn't alter the ranked pool of MMR. He affects the normal pool, but that doesn't matter. Particularly if we consider that a person's normal MMR ceases to influence their ranked MMR the moment they play their first ranked game, the over-time inflation of the normal MMR pool has no bearing toward inflating ranked MMR.



But it raises the question of how the conversion between unranked and ranked MMR works. Does it assign MMR based on relative averages, is it based on the value of unranked? If the unranked MMR inflates, and then that inflated number is just thrown into the ranked MMR pool, that would just siphon the inflation over.



It's an interesting question that I don't know the answer to. But it raises the question of how the conversion between unranked and ranked MMR works. Does it assign MMR based on relative averages, is it based on the value of unranked? If the unranked MMR inflates, and then that inflated number is just thrown into the ranked MMR pool, that would just siphon the inflation over.It's an interesting question that I don't know the answer to. dota 2 stream #noskill #feed #noob twitch.tv/dmcredgrave

Buckyman Profile Joined May 2014 1362 Posts #15 Game modes are an even more twisted complication than Regions. A player's ranked MMR is supposed to reflect how well they play AP, CM and CD. A player's unranked MMR is supposed to reflect how well they play whichever game modes are their most common. And the player populations behave differently across game modes.



In my specific case, I was calibrated into ranked based mostly on game modes that don't even exist in ranked.

Kuroeeah Profile Joined February 2013 7937 Posts #16 The calibration is mostly accurate and I think it takes something relatively absurd into account like KDR.



I have a main account and a smurf, one of my accounts has around two-three times as many games played but the other account has a significantly higher win rate. both accounts ended up with identical MMRs after I finished the calibration matches and ended up being pretty surprised/impressed

Acritter Profile Joined August 2010 Syria 4698 Posts #17 Even assuming MMR inflation was a thing, it would require a high turnover of new accounts to be relevant in a short timespan. MMR has been out for a year, and it's already pretty stable. The only oddities to it are at the very top of the spectrum, where we have players who can reliably win against the other highly-ranked players and who get practically endless MMR growth based on that.



5k is potential professional caliber. 6k is potential professional caliber for someone who plays a lot of ranked. Well over 6k is someone who spams ranked. If that morphs over the next year or so, then you might have some validity to your claim, but right now we've only seen effects of separating players out. dont let your memes be dreams - konydora, motivational speaker | not actually living in syria

HollowLord Profile Joined August 2010 United States 136 Posts Last Edited: 2014-09-17 20:32:01 #18 On September 18 2014 05:24 Acritter wrote:

Even assuming MMR inflation was a thing, it would require a high turnover of new accounts to be relevant in a short timespan. MMR has been out for a year, and it's already pretty stable. The only oddities to it are at the very top of the spectrum, where we have players who can reliably win against the other highly-ranked players and who get practically endless MMR growth based on that.



5k is potential professional caliber. 6k is potential professional caliber for someone who plays a lot of ranked. Well over 6k is someone who spams ranked. If that morphs over the next year or so, then you might have some validity to your claim, but right now we've only seen effects of separating players out.



Inflation isn't really the core of my claim. Inflation is going to happen, it's inevitable with a system like that, but what's more important are the growing discrepancies between regions, at least that's what I claim. And if there's even one game played where the system's probability is faulty, then the entire system is a faulty system.



What I'm suggesting is that, at its core, the Matchmaking System does not always work as intended. It provides false positives to 50-50 odds and I don't think that the consequences of something like that should be taken so lightly. Inflation isn't really the core of my claim. Inflation is going to happen, it's inevitable with a system like that, but what's more important are the growing discrepancies between regions, at least that's what I claim. And if there's even one game played where the system's probability is faulty, then the entire system is a faulty system.What I'm suggesting is that, at its core,It provides false positives to 50-50 odds and I don't think that the consequences of something like that should be taken so lightly. dota 2 stream #noskill #feed #noob twitch.tv/dmcredgrave

FHDH Profile Joined July 2014 United States 7023 Posts Last Edited: 2014-09-17 20:41:17 #19 On September 18 2014 05:27 HollowLord wrote:

Show nested quote +

On September 18 2014 05:24 Acritter wrote:

Even assuming MMR inflation was a thing, it would require a high turnover of new accounts to be relevant in a short timespan. MMR has been out for a year, and it's already pretty stable. The only oddities to it are at the very top of the spectrum, where we have players who can reliably win against the other highly-ranked players and who get practically endless MMR growth based on that.



5k is potential professional caliber. 6k is potential professional caliber for someone who plays a lot of ranked. Well over 6k is someone who spams ranked. If that morphs over the next year or so, then you might have some validity to your claim, but right now we've only seen effects of separating players out.

What I'm suggesting is that, at its core, the Matchmaking System does not always work as intended. It provides false positives to 50-50 odds and I don't think that the consequences of something like that should be taken so lightly. What I'm suggesting is that, at its core,It provides false positives to 50-50 odds and I don't think that the consequences of something like that should be taken so lightly.

This is why I refer to it as a sorting mechanism. If a player skews the perceived 50-50 odds in a match he should continue to sort upwards relative to the players in that match, who, if they belong at that level should return to equilibrium. This is why I refer to it as a sorting mechanism. If a player skews the perceived 50-50 odds in a match he should continue to sort upwards relative to the players in that match, who, if they belong at that level should return to equilibrium. После драки кулаками не машут (Don't shake your fist when the fight is over)

Mandalor Profile Joined February 2003 Germany 73 Posts #20 Can anyone explain this inflation thing to me?

This might be a ridiculously dumb question, but wouldn't there only be inflation at the very top of the spectrum? Afaik the system aims to keep everybody at 50% winrate and since you gain the same point for wins as you do for losses, you should stay at your MMR (assuming you don't improve drastically and get over 50% consistently).

I understand that pros will always gain MMR since you can't have 10 evenly matches pros in every pub game (or at all, I suppose), but how would MMR inflate for the average joe (anything from 2k to 4k I guess)?

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