Currently Overwatch factors individual performance into the calculation for the change in skill rating (SR) after a player wins or loses a match. A commonly-held belief is that there are playstyles on some heroes that make your individual performance with that hero seem better than that of your peers, but don’t contribute enough to your teams chance of winning. If this were true, by onetricking (either exclusively or spending the vast majority of your playtime playing) a less popular popular hero and adopting such a playstyle, you can inflate your SR gains ( and therefore your SR) to a point where it no longer accurately reflects your contribution to your teams chance of winning. This claim, however, to my knowledge, remains unproven. This post is NOT about whether or not onetricks should be tolerated.

The SR difference calculator supposedly takes at least the following factors into account:

Whether or not you won the match

The likelihood of you winning that match beforehand

Your MMR (MatchMaking Rating), which is unknown

Your individual performance on the heroes you played compared to other people playing the same hero at your rank

A playstyle that makes the SR difference calculator think that your individual performance is exceptionally good despite not helping your team achieve victory would theoretically cause a player to achieve a rank where having them as a teammate would reduce a teams likelihood of winning when compared to a player who does not have such a playstyle. So the best way to determine whether or not players who onetrick do indeed have such a playstyle is to compare their winrates to players of a similar rank. If they have a winrate that is significantly lower than that of players in a similar rank, it would imply that their playstyle does ‘trick’ the matchmaker into inflating their SR.

By gathering the career profiles of over 1000 high-ranked players (top 5% assuming the distribution since competitive season 3 hasn’t changed significantly), I was able to plot the average winrate of players vs their skill rating at the higher ranks.

All players in this dataset have played over 15 hours this competitive season, in order to allow their winrates to ‘stabilize’

In GM (4000 SR) and above, a players winrate tends to be higher as their SR increases.

I defined a onetrick as someone who has over 75% of their playtime on one hero. I chose this because at this percentage the majority of their individual performance ‘bonus’ will come from that one hero. While a higher percentage would, of course, minimize the impact of other factors I haven’t accounted for, it would also mean that fewer players would fall into the definition of onetrick. 75% seems like a good compromise between the two.