2023-06-30

[public] 12.3K views, 30.3K likes, dislikes audio only

Sebastian Lague

Trying to improve an old chess bot by experimenting with various interesting techniques.

You can play (or watch) the bot on lichess: https://lichess.org/@/CodingAdventureBot/playing

This is a sequel to: /youtube/video/U4ogK0MIzqk

If you'd like to support my work (and get early access to new videos and projects) you can become a patron of the channel over here: https://www.patreon.com/SebastianLague

Source code: https://github.com/SebLague/Chess-Coding-Adventure

A really fun video about various algorithms for playing chess by @tom7:

/youtube/video/DpXy041BIlA

Music and other credits:

https://github.com/SebLague/Misc-Project-Info/blob/main/Coding-Adventures/Chess-2.txt

Chapters:

00:00 Intro

00:38 Battle of the Bots

03:18 Maybe Don’t Throw Away the Best Move?

07:13 Transposition Troubles

10:55 Search Extensions

14:01 Refactoring and Recapping

15:51 Tweaking Kings and Pawns

19:35 Bitboards!

23:54 Passed Pawns (and more)

28:32 Magic Bitboards (minus the magic)

34:40 The Magical Part of Magic Bitboards

39:00 Testing and Optimizing Move Generation

41:50 Killers, Reductions, and Repetitions

45:56 Creating a Lichess Bot

49:30 Let’s Play!

54:54 Existential Crisis

55:02 The Bot’s First Game Online

56:12 Can Our Bot Beat Stockfish? (No)

56:59 Rating Speculation

59:28 Outro