marco cognetta theoretically good with computers
The Lichess Game Compressor's Analysis of Game 1 of the World Championships
That's right, the Lichess chess game compression model has some key insights for us.
Note: This post can also be found on Lichess and Bluesky.
Note 2: This post is satirical. I mean the numbers and stuff are real and actually drawn from the compressor, but the commentary is not.Trained on millions of games, the Lichess compression model converts moves to bits depending on how good they are. Pretty sure it can give Stockfish a run for its money. Let's see how accurate Gukesh and Ding were in game 1.
Gukesh agreed with the Lichess Compressor's best move 6 times out of 42. Ding, on the other hand, agreed just twice. A sad showing. On average, they both chose the ~11th best moves with medians of 10.5 and 8, respectively. Is this what you would expect from potential World Champions?
In particular, the Lichess compressor noted one massive blunder by Ding: 18. ... Nb2??. This is the 47th best move out of 49 available moves in the position. Insanity. The Lichess compressor recommends the far better Nxe5!!.
From an entropy standpoint, we see a clear difference in play. The Lichess compressor uses an average of ~4.4 bits per move for encoding. Gukesh and Ding required an average of 4.98 and 5.21 bits, respectively, indicating that they deviated significantly from established thought.
Gukesh required 209 bits to encode his moves while Ding required a whopping 219! Of that, an enormous 14 bits were needed for his catastrophic Nb2?? blunder. That's more than 6% of the encoding!
We should all pray for Lichess and whoever is covering their storage costs if this is the future of chess.
On an unrelated note, I once made a Lichess bot that used the compression function as an evaluation function. It didn't win a single game.
Appendix
If you are interested in producing your own graphs like the ones in this article, here is a Colab that can convert a PGN input or a Lichess game into a graph.
If you are interested in running the Lichess compressor bot (a Lichess bot that uses the compression scorer as an evaluation function), a repo and instructions are given here.