A Statistical Analysis of how Matchmaking is Unfair. Should the Team ELO or Map Should Be Balanced?

TL;DR - Win rates for games with evenly ranked players is 60% in favor of blue side, so riot's matchmaking algorithm statistically puts better players on red side to even out the win rate. I find that to be a poor solution, and would prefer to play evenly ranked players with a map disadvantage (although fixing the map or coming up with new and creative solutions would be ideal).

Maybe I would have better luck on Reddit, but my focus is letting Riot know my concerns not just the player base.

My analysis consisted of 41,899 52,000 Silver to Diamond games during the 6.9 patch. When I refer to ELO I am using the formula that LoLKing uses (I posted my code in a comment below along with a few graphs that were requested). It is a number that represents what division and tier the player is in. For example, A Gold III player will have a higher ELO than a Silver IV.

My results show that if two teams are nearly even in ELO scores then the blue team wins 60% of the games. Before the argument of, "but LoLKing says red and blue's win rate is 50/50" comes out let me make sure that we all are on the same page. Yes, the win rate of blue and red is 50/50, but when players are evenly ranked in ELO scores blue has a substantial advantage. The fact that the blue and red win rates are 50/50 suggests that the algorithm is artificially stacking red team with better players to keep the balance. This can be further substantiated in that my analysis shows that ~65% of the time red team is given the higher ELO team.

If you still don't understand here is a simple example: A soccer field has on goal that is much larger than the other. Obviously it is easier to score in a larger goal so one team will have an advantage. Riot's solution seems to be to put the best players on the side with the large goal hoping it will balance out the fact that they will be shooting on the smaller goal. Unfortunately this is very flawed logic.

This is flawed because you cannot prove that you are actually balancing the matches rather than just rigging them. I could get 50/50 blue/red win rates by putting 5 diamond players on one team and 5 bronze players on the other and alternate which side the diamond team is playing on. This would easily artificially create the illusion that the sides are balanced when they are not.

Using a support vector machine (SVM) learning algorithm I was able to predict who was going to win a match ~64% of the time solely based on the ELO of the players and the side they were playing on.

This suggests one of two things may be going on:

1. Riot's match making system needs major work as it doesn't work very well
2. Riot's match making system is (perhaps unintentionally) stacking teams to give the appearance that the map is balanced.

If Blue side win's too many games does the algorithm make sure that it goes back to 50/50 by increasing the deviation of elo placed on the red team as compared to blues'?

I think it goes without saying that this is a broken system.... So why does Riot just not fix the map? Well I think they have tried. Rift herald, brush changes, etc. were all changes in attempting to balance the map. It is probably expensive, time consuming, and may cause community backlash (probably not as much if people realized how bad it currently is).

I personally would much rather play evenly ranked teams, even if I had a disadvantage due to the map. In fact it is likely a more balanced solution as well. Like I said, I can predict who will win 64% of the time when given the ELO of each team, but evenly matched games give only a 60% accuracy of who will win. This would imply that it may be possible to gain a 4% better 'balance' to the game by allowing the map to be unbalanced, but ensure teams are even as possible. Since it is impossible to always have perfectly even teams, you could potentially further improve balance by always putting the higher ranked team on the red side.

The statistic that makes me the most angry is that when blue side has a significant advantage in ELO, they have a 70% chance of winning. What is more upsetting is that this accounts for around ~10% of total games. That means statistically 1 out of 10 games you are heavily disadvantaged. Why was that team placed on blue if the odds were known to be that bad? Answers I don't have.

What do y'all think? Is this how Riot should be balancing the win rates? Should the map be tweaked? Should it be completely redone?

note - I remade this post because I messed up the poll and could not find a way to change it

edit - let players know that I have a graph below edit - tweaked the TL;DR and fixed the number of games used in analysis