I wanted to write a quick little blog post about a trend we are seeing in TvT right now. Early on, I very much liked the 2 base TvT style using Marine / Tank / Medivac. Keep aggressive, utilize those mobile tanks, and float your main CC to your 3rd base when you are ready. Recently I’ve begun to change my opinion on the strength of this opener recently, though…at least on some maps.



Let’s take a look at Cure vs Reality from Proleague on Lerilak Crest https://www.youtube.com/watch?v=B9iIKxuExx4



and we will compare that with Maru vs INnoVation on Ruins of Seras https://www.youtube.com/watch?v=9xRp1z3-2oA



Both games have one player going for a Reaper expand (Reality and INnoVation) into an expansion, with a tech follow-up. Definitely a great opener and a very popular one as well.



Both games also have the challenger (Cure, Maru) opening up with 1 base tech involving some amount of harassment. This includes Cloaked Banshees in both games.



OK, so let me run you through the next steps for each side:



Early Game Defender (the player with the faster expansion, Reality and INnoVation)

- Produce Vikings, Tanks for Defense

- Add on one Engineering Bay for upgrades (2 doesn’t make sense for a build going for 2 base aggression)

- Add Barracks to utilize your swell in minerals from having an earlier expansion

Early Game Aggressor (the player with the faster tech, Cure and Maru)

- Harass as much as possible with early tech units

- Add on 2 Command Centers to make up for how much faster opponent had first one

- Add on 2 Engineering Bays for upgrades (1 doesn’t make sense for a build with a 3 base economy)





OK, so stick with me here. As the early harassment is fended off, the early upgrades of the fast expander start to come online, and the mineral advantage from the faster base starts to pay off in the form of additional Marines, the roles of these players within the game swaps.



Reality and INnoVation become the Mid Game Aggressors



and, of course,



Cure and Maru become the Mid Game Defenders



OK, here we are in the mid game. Time for some damage put on to those early tech into 3 CC players! Let’s take a look at the Unit tabs, both of these screen shots taken seconds before the fighting begins:



CURE (RED) vs REALITY (BLUE)



Notice the important differences:

- Cure has a higher SCV count, as he’s made the 3rd CC and is pushing ahead in economy.

- Reality has more Marines (23 more at this moment), as he’s made the earlier expansion, and thus gained extra minerals, which go into Marines, strengthening his army.

- They have the same amount of Siege Tanks.



MARU (RED) vs INNOVATION (BLUE)



Notice the important differences:

- Maru has a higher SCV count, as he’s made the 3rd CC and is pushing ahead in economy.

- INnoVation has more Marines (21 more at this moment), as he’s made the earlier expansion, and thus gained extra minerals, which go into Marines, strengthening his army.

- They have the same amount of Siege Tanks.



Natural differences according to the opening build orders that they used. The important part to look at is the Siege Tank count. The Siege Tank is the most important unit in TvT, and if one player has an advantage on them, that player is likely to have an advantage in the game itself. It makes sense that the Siege Tank count is lined up. One player in each game did, in fact, get earlier tech buildings. These buildings were used for early game harassment units though, not for Siege Tanks. Around the time that the faster expander starts Siege Tanks, the tech player is pretty much ending his production of harassment based units and is starting Siege Tanks as well. So here we are with the same amount of Siege Tanks on both sides.



While it’s definitely true that Legacy of the Void’s addition of Medivacs picking up Siege Tanks made them much better at attacking than before, as professionals get better and better, they understand how to utilize defender’s advantage with them as well. Being on the defensive here, on many maps, is going to be a position which is doable for a professional. This extra boost in Marine count, while it obviously makes your army stronger, doesn’t mean that you can get in through an entrenched position. Reality vs Cure is a great example of this. It almost doesn’t matter how many Marines that Reality has, if they try to walk through Lerilak Crest’s tiny chokes, they are going to be blown up before their greater numbers matter.



The thing is, the 2 base player -has- to do something. This is the “power spike” of his build. This is when he has an advantage. Backing off and making a later 3rd CC is not going to catch you up that well. Your opponent also has an additional Engineering Bay, and thus will be well ahead on upgrades when he’s ready to move out.



So now that I’ve told you that the 2 base player -has- to do something, I’m going to go back on that, and show that this is is where INnoVation went wrong in his game.



When INnoVation was ready for his attack, he scanned the 3rd base area. Maru hadn’t even landed his 3rd CC yet! Now, Ruins of Seras is a very different map from Lerilak Crest. On Lerilak Crest, Cure was able to build his CC at his 3rd base and mine from it instantly, as it’s back in a pocket with a choke with destructible rocks in front of it. Ruins of Seras has a much more wide open 3rd base. It has a lot of angles that you can attack from. In his game vs Maru, INnoVation was not detoured from Maru’s lack of a 3rd base. INnoVation (rightly) realized that he had an advantage at this point in the game, and he (wrongly) decided to push that advantage at the moment of it’s greatest power (unit-count wise) over Maru. INnoVation pulled an old-school MarineKing here. He dropped into a defensive 2 base player. There was no need. Maru’s build -requires- that he is mining from a 3rd base to properly have an advantage in the later stages of the game. With such an army disadvantage, Maru had no chance of taking his 3rd base with INnoVation’s massive army right outside his door, especially with the amount of attackable surface area that Ruins of Seras’s 3rd base has.



If we super simplify this, there are three periods, with the players taking different risks in each.



If the tech opener (Cure, Maru) don’t do damage in the early game, they are taking the risk of taking damage in the mid game. But then they get another opportunity to hurt their opponents in the late-mid game.



The expand opener (Reality, INnoVation) are taking two risks if we continue this forward. Early game they must defend well (not too hard) and not take too much damage. They then have an opportunity in the mid-game to deal damage. If they do not deal sufficient damage, they are behind in the late-mid game against their opponents who have additional upgrades and economy.



The real pressure in these games was on Reality and INnoVation to get some damage done during the window of their advantage.





