A while back we looked at Radiant vs Dire win rates in 6.74 and 6.77 and found that Radiant had a slight overall advantage that was most pronounced in short games and actually became a disadvantage during long games. While we don’t have absolute proof, it’s generally accepted that the late game Dire advantage is driven largely by the positioning advantage Dire has for Roshan. But when it comes to the other side of the dynamic, Radiant’s advantage during short games, all we have are competing theories with no clear evidence. Recently in League of Legends, a stat site released some data on the balance between their sides in various modes, and the implications could help explain what’s going on.
For those unfamiliar, the LoL Blue team corresponds to Radiant positionally and Purple corresponds to Dire. The default LoL map has some asymmetry, but nothing to the extent found in the Dota map. What the stats show is that on the standard League map, the Blue side has a significant advantage in all modes (Unranked: 56.3%, Ranked: 55.2%, Ranked Teams: 53.5%).
Where things get interesting is that the same advantage exists in ARAM (55.4%) which is a perfectly symmetrical map. This is the strongest evidence I’ve seen that the Radiant advantage is related to the viewing perspective/camera angle. The LoL map with the smallest side advantage is Dominion (51.8%), which also happens to be the only map tested without a diagonal tilt, as the map is East/West symmetrical.
It’s still not proof, but I think there’s decent evidence here in support of the camera angle theories. Dire’s inherent Roshan advantage could actually be rather appropriate. Roshan’s positioning would likely have the greatest net effect in low level games as low level games have the longest average duration. These also might be the players least capable of dealing with the camera disadvantage, and therefore most in need of a larger counterbalance. It’s fairly speculative, but it would be a pretty unique feature if both the Radiant and Dire advantages separately scaled at a similar rate with the overall skill of the players in the game.