Win Rates - What Do They Really Mean?

Introduction

There's been a lot of discussion on the tier lists regarding win rates and how much they should be taken into consideration when picking champions for solo queue.

This article will discuss what win rates do and do not mean, and hopefully also shed some light on the thought process behind placing certain champions on the list.

Summary: With enough playtime, a high win rate on a champion indicates *something* generally goes right, and a low win rate indicates that whatever is happening in games with this champion isn't in their favor.

A low win rate may mean a champion is being played incorrectly and is stronger than his win rate indicates, but a top 25 win rate (with 120 champions) almost always indicates that a champion is at least a good candidate for Tier 1 or high Tier 2 if the sample size is large enough.

Background

The current range of champion win rates lies almost entirely within the range of 45% to 55%. This means that while there are certain outliers, the majority of champions are close to balanced when it comes to players of similar skill levels and any unknown variables that change from game to game.

Definitions:

•          “low win rate” - champions in the lower 25 champion range. This currently comprises of champions at 47% and lower at the time of writing this article.
•          “high win rate” - champions in the upper 25 champion range. This currently makes up champions at 52% or higher.

Note on Statistics:

For those of you who are unfamiliar with statistics, the reliability of the underlying statistics are always based off of a “good” population size. This means that if a champion isn’t played frequently enough, or is a “niche” pick (see below), then the statistics for that champion will be skewed.

Nerfplz's tier lists generally use data from Lolking.net’s page, and thus uses the data that Riot makes available over a broad spectrum of games. However, it doesn’t account for the following:

1.          “Troll” Picks: If a certain champion is selected for the sole purpose of losing, then the results should tend towards a losing team. Reasons include poor team morale and low personal and team effort.
2.          “Niche” Picks: If a certain champion is only selected when a certain other champion is on the enemy team, then the results should tend towards a winning team. Reasons include high morale, higher champion knowledge and effort, and higher chance of winning a specific lane.

Low Win Rates

When a champion has a low win rate it indicates that over the course of the sample size in a range in time, this specific champion has historically underperformed.

What this DOES explain:

1. Whatever people generally do with this champion may not be optimal;
2. This champion's strength may be lower than the majority of other champions; and
3. This champion's core strengths may be heavily outperformed by other, more popular champions in the current meta.

What it does NOT explain:

1.          The potential overall strength of the champion;
2.          The potential strength of a specific rune/mastery/skill/item combination; and
3.         The strength of a champion in a different and shifting meta-game (champion selection, strategies, etc.)

This means that if any of the aforementioned changes or becomes apparent to more of the population, then this champion could experience a sudden increase in win rate and I'll likely experience a sudden increase in complaints in champion placement. (Unless I had the foresight to place them high to begin with, which means I've been getting complaints the entire time - See Wukong)

High Win Rates

These champions have historically won more often than other champions during the times that they're picked.

What this DOES explain:

1. The current most popular item/skill/mastery/runes on that champion appear to be working; 
2. This champion's combination of damage, utility, and survivability seem to be line with the majority of other champions currently popular; and
3. The times when this champion is selected are favorable to that champion (may be a counterpick, but if the pick percentage is high enough, this seems unlikely.) 

What this does NOT explain:

1. That this champion is a good champion to pick in every scenario; 
2. That a top 10 win rate champion is necessarily better than a top 20; and
3. That this champion will win their lane match-up more often then not.

Conclusion

There are numerous ways to win or lose a game. Every day, the metagame shifts and certain champions move in and out of popularity. All the while, Riot nerfs and buffs champions on a consistent basis in the name of balance.

While statistical analysis won't be the end all to champion selection and team synergy, in solo queue at least, a champion's win rate should be looked at if it stands out far ahead or far behind of the pack. This generally signals that there's either untapped potential or meta sheep bias at work.

However, since most win rates generally lie within a similar spectrum, great care should be taken when saying that a 54% win rate champion is significantly better than a 52% win rate champion. Despite the fact that the difference in the two may very well be over 20 places, their overall success is still very similar.

What do you think? Agree/Disagree? Post your thoughts below!