|Blue Side Win Rate vs Game Length, Gold-level NA Ranked Solo Queue on Patch 5.7|
For those who are unaware, it was discovered around this time last year that the blue side (bottom side) was winning 55% of the time on Summoners' Rift. At the time, there were quite a bit of speculations on why this was happening and several theories were proposed. At the end of the day, it seemed that the issue was almost certainly due to the camera angle. In June of 2014, Riot decided to change the matchmaking algorithm to put the higher Elo team on the purple side,
One thing I missed from last year was that this "Blue Side Advantage" seems to be stronger for shorter games. Even after the matchmaking adjustments, blue side seems to excel in shorter games -winning 53.5% of games between 20 to 30 minutes. However, for longer games (>40 minutes), blue side's chance of winning drops below 50%. The similar effect can be detected in old Season 4 games before Riot's matchmaking adjustments that made the stronger team on the purple side; therefore, it is unlikely that the pattern is solely caused by stronger players being better at later stages of the game.
|Blue Side Win Rate vs Game Length, Gold-level NA Ranked Solo Queue on Patch 4.7 (before Riot's matchmaking changes)|
My personal opinion on the matter is as follows. It is possible that being on the blue side gives a sizable advantage in the earlier stages of the game due to favourable camera angle. As the time goes on, the effect diminishes and the advantage of playing on blue side decreases.
Assuming my hypothesis above is true, and also assume that the same logic for solo queue data can be applied to competitive games, does this mean that a professional team playing on the purple side should play the game differently to compensate for their early game disadvantage? Does this mean that purple side should consider picking champions that are stronger in the early game in order to compensate for their early game disadvantage? This is just a hypothesis, of course, and it is really difficult to answer in either direction. Nevertheless, it is something interesting to think about.