Ratings - Chess.com Vs Lichess.org - A Deep Look

The Skill Myth:

Higher Knowledge about Chess = Higher rating right? Well, not necessarily. Knowledge about the game and rating are separate things. They do relate to each other, but I believe it is important to make a distinction: Knowledge is the base currency that players need in order to perform well; rating tells us about consistency of performance. If a guru of chess made a big mistake every 10 moves, but played the other 9 perfectly, that guru would have a lower rating than if he only made a mistake once every 20 moves.

1. Rating measures consistency of performance relative to peers.
2. Rating does not tell you your skill at the game of chess - it merely positions you relative to a group of players based on your consistency vs those players.

The rating pool at chess.com:

The blitz rating pool at chess.com is positioned around an average player at 648.1 rating points. If players are normally distributed around that average, that means that 68% of blitz players on chess.com will fall pretty close to the 648 rating mark. You'll notice in the below image that players are not evenly distributed around average. The player pool is skewed with more players squished to the left side of average, and a long tail of players to the right, far from average.

The rating pool at lichess.org:

The average player at lichess.org is harder to pick out, because the metric is not listed prominently. We can make an educated guess that it is pretty close to 1500 on the below distribution graph. The Lichess.org rating pool is close to a normal distribution, where 68% of players will fall pretty close to the average player.

Now ask the question: Is the average player on lichess.org more knowledgeable than the average player on chess.com? I don't have any evidence to suggest that they are, or are not. If you followed my opening argument, you would know that it doesn't even matter which average player is more skillful. The honest truth is that an average player on chess.com wins an average amount of the time within chess.com's pool of players. The average player on lichess.org wins an average amount of time versus the players within lichess.org's own pool.

These two rating pools: one at chess.com, and one at lichess.org, are separate things that measure performance in separate places versus different people. They have no meaning together, so let's not mix them or try to compare (except for entertainment). By the way, my blitz rating on chess.com is 2348, and my Lichess blitz rating is 2299. Fun to compare, and meaningless!