Back in 2018 I tinkered around with SashChess and considered it interesting. It's based on Stockfish and I recently tested it in a Lechenicher SchachServer tournament where engine use is allowed and there was little difference between SashChess and whatever engines my opponents were using...all of the games were uneventful draws. Conclusion: there was no advantage to using it over SF15.
Today I took a quick look at Leela Chess Zero (abbreviated as LCZero, lc0), a free, open-source, deep neural network–based engine. It starts with no chess knowledge other than the basic rules and then learns how to play by learning from playing against itself.
As of November 2022, it has played over 970 million games against itself and the claim is that it's capable of playing at a level that is comparable with Stockfish. I don't think so because I have seen no evidence to back up the claim.
On the CCRL 40/15 rating list Lc0 0.28.0 w744204 64-bit 4CPU
is ranked 22-24 with a rating of 3372. Against Stockfish 15 it's score is +0 -15 =17
On my laptop I ran a test, a 4 minute per game match pitting Lc0 v0.22.0 against Stockfish 15. Both engines had a hash size of 1125 (about half of what was available), but Lc0 v0.22.0 inadvertently was given a handicap of 2 CPUs to 1 CPU.
I stopped the match after 18 games. The result: Stockfish scored +15 -0 =3.
Again, I see no evidence that Lc0 is to be preferred over Stockfish.
After the game was over, stepping through it with Lc0 it seems that the engine does not perform well at fast time limits. However, after being given some time to ponder over it's next move, it changes its mind and will select a better move, but not always one that agrees with Stockfish's selection.
Here is an example of Lc0's play.
Lc0 v0.22.0–Stockfish 150–1C18Blitz Match G/4Deep inside my PC12.2022Stockfish 15
French Defense 1.e4 e6 2.d4 d5 3.c3 b4 4.e5 c5 5.a3 xc3+ 6.bxc3 e7 7.h4 An interesting line that has a high success rate
in my database. Much more usual is 7.Qg4 c7 8.h5 aiming for h6. h6
Preventing the further advance of the h-Pawn, but black has another
interesting alternative. 8...cxd4 9.cxd4 c3+ 10.d2 xd4 with equal
opportunities. 9.d2 bc6 White's next move, while not really an error,
seems to be heading down the wrong path. Either 10.Nf3, or, perhaps, 10.Bb5+
seem better. 10.g4 f5 11.f3 cxd4 12.cxd4 0-0 12...cxd4 is inviting,
but it allows white to gain a slight advantage. 13.xd4 xe5+ 14.e3 xe3 15.b5+ f8 16.fxe3 xe3+ 17.e2 e5 18.d7 e7 18...c5 is no better. 19.f1 f6 20.d1 a5+ 21.c3 xd7 22.xd7 d8 23.xb7 g8 White is
winning. Quesada Perez,Y (2626)-Feng,M (2198) Philadelphia 2019 19.h3 g5 20.xc8 hxc8 White is better, but in Yu,Y (2607)-Kotsur,P (2559) Moscow
2011 he was unable to score the point and only drew. 13.d3 This results
in some interesting tactics! Defending the d-Pawn with either 13.c3 or 13.Rd1
would have resulted in a position that was nearly equal. It's interesting that
Lc0 initially thought it was better by about half a P after this move. After
being given a couple of minutes to mull things over it decided the position is
equal, but 13.Qf4 would have been just a bit better. After actually making the
move 13.Bd3 it realized that black stands better by, it thinks, about half a P.
Stockfish's evaluation is that the position is 0.00. fxd4 14.xh6 An
ingenious counter stroke that is met by an equally clever reply. 14.xd4
is met by xe5+ 15.e3 f5 16.h4 f4 with a strong initiative. 14...f5 15.exf6 15.g3 was somewhat better. xf3+ 16.gxf3 16.xf3 xe5+ wins 16...xe5+ 17.xe5 xe5 18.e3 f4 18...xd3+ 19.cxd3 is only equal
because of Bs of opposite color plus black has the bad B. 19.c5 f6 20.0-0-0 xd3+ 21.xd3 with an equal position. 15...xf3+ 16.gxf3 16.xf3 allows black to land a walloping blow with xf6 17.d1 xh6 16...xf6 16...e5+ is much worse. 17.d2 xf6 18.g5 and white has equalized. 17.xg7 A serious (and losing) tactical error by Lc0. 17.e3
would have been better, but after e5 black still has the better of it. 17...xg7 18.h4 h6 Also good was 18...Rxf3 19.g1+ h8 20.g3 d7 21.b1 e5 22.xb7 LcO misses the mate, but the game was quite lost anyway. 22.g5 was the best move available, but after d4 23.e2 xg5 24.xg5 c6 25.xe5 xc2+ black is winning. 22...c1+ 23.e2 d4# Quite poorly played
by Lc0 0–1
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