MAIA CHESS

I used to play computer chess against my Power Fritz 18 chess program. I really shouldn’t say, “used to play”, because I still do play Fritz when I get cocky and start to think I’m getting ‘good’. I played at 1705 rating level, rated play (no takebacks), with a time constraint of 1 hr. Fritz uses the Stockfish 16 chess engine. After 60 games, it says my playing level is “Ambitious Club Player”...whatever the "Ambitious" means. ha It also says my score is 8%. I’m assuming that means I only beat Fritz 8% of the time which is about right. My current rating, according to Fritz is around 1550.

So, to put it mildly, Fritz kicks my butt. And, I’m getting tired of Fritz kicking my butt. It’s no fun getting your butt kicked in chess 92% of the time. Don’t get me wrong, my games are always close with Fritz. But, where Fritz really shines is the Endgame. I have never won an Endgame against Fritz- with equal positions. It just knows where every piece should be placed for optimal play. The most I could ever hope for is/was a draw.

Enter Lichess. I started playing against Lichess on its PLAY WITH COMPUTER option. When you play against the Computer (in Lichess) you have eight (8) levels to choose from. Lichess uses the Stockfish chess engine, just like my Power Fritz 18 chess program. The levels are:

Stockfish 1 (SF1)= 800 rating (Beginner)
Stockfish 2 (SF2)= 1100 rating (Intermediate)
Stockfish 3 (SF3)= 1400 rating (Advanced intermediate)
Stockfish 4 (SF4)= 1700 rating (Club player)
Stockfish 5 (SF5)= 2000 rating (Club tournament player)
Stockfish 6 (SF6)= 2300 rating (Expert/Master)
Stockfish 7 (SF7)= 2700 rating (International Master)
Stockfish 8 (SF8)= >2700 rating (Grandmaster)

I played at the Stockfish 4 level (1700 rating). I’m not sure of my Win-Loss-Draw percentage, but I’m pretty sure I was close to 50%-50%-0% WDL. Much better/easier than Power Fritz 18 played at a similar rating. When you play at Stockfish level 4, the computer only looks ahead 7 moves compared to 15 moves ahead on Stockfish level 8.

But, you can see from the graph below, it doesn’t do it with very high accuracy. So, when I’m playing Stockfish 4 level (1700 rating) Lichess is only 38% accurate. The accuracy refers to “move-matching” accuracy to that of a human.

Source: University of Toronto, Computer Science Dept

Is there a chess engine that plays more like a human, with better move matching accuracy?
Enter Maia. Maia is an engine designed to play like humans at a particular skill level. To achieve this, the developers adapted the AlphaZero/Leela chess framework to learn from human games. See my other blogs re: AlphaZero/Leela. The developers created 9 different versions, one for each rating range from 1100-1199 to 1900-1999. They made 9 training datasets, with each training set containing 12 million games. Then, they trained a separate Maia model for each rating bin to create 9 Maias, from Maia 1100 to Maia 1900. Maia 1100 is designed to play like a human player who is rated 1100-1199 (beginner) and Maia 1900 is designed to play like a human player who is rated 1900-1999 (expert level).

Instead of trying to find the best possible move in a chess position, like the Stockfish chess engine, Maia uses the training data to find the move that would most likely be made by a human. For a given chess position, Maia selects the move made by a human roughly 50% of the time. The result is a chess program that plays very much like a human. See graph below.

https://lichess.org/@/mullerrj/blog/newSource: University of Toronto, Computer Science Dept

Over half the time, Maia 1900 predicts the exact move a 1900-rated human played in an actual game. For this reason, I’ve stopped playing at Stockfish Level 4. Instead I play against the Maia9 BOT on Lichess. It can be found, on the COMMUNITY tab, under Players, Online bots:

I play the BOT maia9, which is currently playing to a 1728 rating in Classical play. With Maia9, I believe my Win-Draw-Loss is 14-19-1 (33 games). That’s a 42% win rate which is much better than Power Fritz’s 8% (60 games). Now you know why I like playing Maia9 rather than Power Fritz 18 at the 1700 level rating. It makes me feel like I’m a better player. Plus, I’ve been on a roll lately. I’ve won 5 of my last 6 games against Maia9. It’s made some bad blunders lately. The blunders were so bad that I commented to Lichess about it. I don’t feel so good when I beat a computer or human when they blunder. But, I guess that’s chess! Like I said, I’ll have to go back and play Power Fritz 18 to humble me quickly.

I like Maia9, and I think you will too. Give it a try and see what you think. Let me know. It plays more human-like (better move-matching accuracy) than Stockfish or Leela.

Source: Miaichess.com