Ember - new UCI engine written on Rust

[DreamerExx]

Awesome
[pgn][Event "My Tournament"]
[Site "?"]
[Date "2026.06.17"]
[Round "2"]
[White "EmberNNUE"]
[Black "Naum"]
[Result "1-0"]
[ECO "D07"]
[GameDuration "00:00:29"]
[GameEndTime "2026-06-17T10:28:44.159 RTZ 2 (зима)"]
[GameStartTime "2026-06-17T10:28:14.187 RTZ 2 (зима)"]
[Opening "Queen's Gambit declined"]
[PlyCount "129"]
[TimeControl "8+0.08"]
[Variation "Chigorin defense"]

1. d4 {+0.49/1 0.001s} d5 {-0.23/13 0.23s} 2. c4 {+0.31/1 0s}
Nc6 {-0.03/11 0.23s} 3. Nc3 {+1.15/1 0s} e6 {-0.12/11 0.19s}
4. Nf3 {+1.12/13 0.32s} Nf6 {-0.05/12 0.24s} 5. Bg5 {+1.15/11 0.32s}
Bb4 {+0.22/11 0.19s} 6. e3 {+1.16/12 0.31s} O-O {+0.03/12 0.33s}
7. Rc1 {+1.65/10 0.30s} h6 {+0.06/11 0.46s} 8. Bh4 {+1.69/11 0.29s}
Re8 {+0.07/11 0.66s} 9. a3 {+1.29/9 0.29s} Bxc3+ {-0.13/11 0.31s}
10. Rxc3 {+1.32/13 0.28s} g5 {-0.25/11 0.29s} 11. Bg3 {+2.44/13 0.28s}
Ne4 {-0.17/11 0.13s} 12. Rc1 {+1.93/11 0.27s} h5 {-0.07/10 0.13s}
13. h3 {+2.32/9 0.26s} Nxg3 {-0.28/10 0.51s} 14. fxg3 {+1.92/10 0.26s}
e5 {-0.19/10 0.13s} 15. cxd5 {+2.91/9 0.25s} Qxd5 {-0.27/11 0.12s}
16. Bc4 {+3.56/8 0.25s} Qa5+ {-0.16/10 0.32s} 17. Nd2 {+3.56/9 0.24s}
exd4 {-1.17/10 0.51s} 18. O-O {+3.56/7 0.24s} Be6 {-1.23/10 0.23s}
19. Ne4 {+3.22/7 0.23s} Qe5 {-0.58/10 0.18s} 20. Nf6+ {+2.80/7 0.23s}
Kg7 {-0.79/11 0.13s} 21. Nxe8+ {+3.64/6 0.22s} Rxe8 {-0.79/6 0.016s}
22. exd4 {+3.10/8 0.22s} Qxd4+ {-0.84/12 0.17s} 23. Kh2 {+3.68/9 0.21s}
Qxd1 {-0.69/11 0.13s} 24. Rfxd1 {+4.30/10 0.21s} Bxc4 {-0.66/12 0.067s}
25. Rxc4 {+4.21/11 0.20s} Kf6 {-0.69/13 0.20s} 26. Rc5 {+4.91/8 0.20s}
Re2 {-0.74/13 0.16s} 27. b4 {+4.52/7 0.20s} Re7 {-1.12/12 0.21s}
28. Rdc1 {+5.21/8 0.19s} a6 {-1.51/11 0.081s} 29. h4 {+5.97/8 0.19s}
gxh4 {-1.48/12 0.082s} 30. gxh4 {+5.94/8 0.19s} Re3 {-1.49/13 0.092s}
31. R1c3 {+6.84/8 0.18s} Rxc3 {-1.53/14 0.065s} 32. Rxc3 {+5.78/10 0.18s}
Ke6 {-1.98/14 0.19s} 33. Rc5 {+7.14/9 0.18s} f5 {-2.05/14 0.083s}
34. Kh3 {+6.74/9 0.17s} Kf6 {-2.43/12 0.077s} 35. Kg3 {+7.84/9 0.17s}
Ke6 {-2.58/13 0.12s} 36. Kf4 {+9.20/9 0.17s} Ne7 {-2.65/14 0.071s}
37. Kg5 {+9.15/9 0.17s} c6 {-2.76/14 0.14s} 38. Rc2 {+9.09/8 0.16s}
Nd5 {-2.81/12 0.095s} 39. Re2+ {+9.92/9 0.16s} Kd6 {-3.19/13 0.26s}
40. Kxf5 {+9.63/8 0.16s} b6 {-3.27/14 0.23s} 41. Re6+ {+9.96/6 0.15s}
Kd7 {-3.27/13 0.19s} 42. g3 {+9.70/8 0.15s} Nc3 {-3.02/13 0.18s}
43. Re3 {+10.70/8 0.15s} Nd5 {-3.20/14 0.15s} 44. Re5 {+10.66/8 0.15s}
b5 {-3.37/12 0.12s} 45. Kg6 {+11.88/9 0.15s} Nb6 {-4.13/13 0.18s}
46. Rxh5 {+14.72/8 0.14s} Nc4 {-4.17/13 0.14s} 47. Rg5 {+15.69/8 0.14s}
a5 {-6.23/11 0.17s} 48. h5 {+16.34/10 0.14s} axb4 {-7.22/11 0.14s}
49. axb4 {+17.34/8 0.14s} Ke6 {-10.12/12 0.17s} 50. h6 {+17.41/8 0.14s}
Nd6 {-10.14/12 0.17s} 51. h7 {+17.84/8 0.14s} Nf7 {-10.19/12 0.091s}
52. Rh5 {+18.63/6 0.13s} Ke7 {-10.19/13 0.17s} 53. Rf5 {+21.42/8 0.13s}
Nh8+ {-10.21/10 0.099s} 54. Kg7 {+22.61/10 0.13s} Ke6 {-10.20/10 0.096s}
55. g4 {+23.88/9 0.13s} c5 {-M24/10 0.17s} 56. Kxh8 {+28.23/9 0.13s}
c4 {-M22/9 0.067s} 57. Kg7 {+29.08/7 0.13s} Kd6 {-M16/8 0.027s}
58. Kf6 {+34.06/9 0.12s} Kc6 {-M16/7 0.023s} 59. h8=Q {+46.33/5 0.12s}
Kb6 {-M14/5 0.018s} 60. Qb8+ {+47.20/5 0.12s} Ka6 {-M10/3 0.016s}
61. Qxb5+ {+47.39/5 0.12s} Ka7 {-M8/3 0.016s} 62. Qd7+ {+M7/6 0.12s}
Ka8 {-M8/3 0.015s} 63. Qc8+ {+M5/6 0.12s} Ka7 {-M4/3 0.016s}
64. Qc7+ {+M3/6 0.12s} Ka6 {-M2/3 0.015s} 65. b5# {+M1/6 0.12s, White mates} 1-0[/pgn]

[DreamerExx]

RELEASED!!!
I present to you Ember 1.0.0. According to my measurements, it has around 2700 Elo.
Release link: https://github.com/ExxDreamerCode/Ember ... tag/V1.0.0

[ericlangedijk]

I played a few games against my engine.
Ember plays quite ok

I did not have a look at the code (I avoid Rust since my own traumatic experience with it).
I would turn off the openingsbook by default. But that is personal.

[DreamerExx]

I played a few games against my engine.
Ember plays quite ok

I did not have a look at the code (I avoid Rust since my own traumatic experience with it).
I would turn off the openingsbook by default. But that is personal.

Thanks for the feedback!

[DreamerExx]

I played a few games against my engine.
Ember plays quite ok

I did not have a look at the code (I avoid Rust since my own traumatic experience with it).
I would turn off the openingsbook by default. But that is personal.

What's the score?

[NichtElias]

I had Ember 1.0.0 play against my engine for fun and the result was this game:

[pgn][Event "Engine Match"]
[Site "En Croissant"]
[Date "2026.06.18"]
[Round "?"]
[White "Erinn"]
[Black "Ember 1.0.0"]
[Result "1/2-1/2"]
[Orientation "white"]
[TimeControl "60+1"]

1. e4 {[%clk 0:01:00] } e5 {[%clk 0:01:00] } 2. Nf3 {[%clk 0:00:58.641] } Nc6 {[%clk 0:01:00.996] } 3. d4 {[%clk 0:00:56.216] } exd4 {[%clk 0:01:01.996] } 4. Nxd4 {[%clk 0:00:53.593] } Bb4+ {[%clk 0:01:02.993] } 5. c3 {[%clk 0:00:52.355] } Bc5 {[%clk 0:01:03.99] } 6. Be2 {[%clk 0:00:50.404] } Nf6 {[%clk 0:01:04.99] } 7. Nxc6 {[%clk 0:00:47.136] } bxc6 {[%clk 0:01:03.159] } 8. e5 {[%clk 0:00:41.722] } Ne4 {[%clk 0:01:01.386] } 9. O-O {[%clk 0:00:40.487] } Qh4 {[%clk 0:00:59.668] } 10. Qe1 {[%clk 0:00:39.78] } O-O {[%clk 0:00:58.004] } 11. Bf3 {[%clk 0:00:37.824] } d5 {[%clk 0:00:56.392] } 12. exd6 {[%clk 0:00:36.401] } f5 {[%clk 0:00:54.83] } 13. g3 {[%clk 0:00:35.388] } Qf6 {[%clk 0:00:53.317] } 14. dxc7 {[%clk 0:00:34.236] } Ba6 {[%clk 0:00:51.851] } 15. Be2 {[%clk 0:00:33.38] } Nxf2 {[%clk 0:00:50.431] } 16. Rxf2 {[%clk 0:00:31.95] } Rae8 {[%clk 0:00:49.055] } 17. c4 {[%clk 0:00:31.078] } f4 {[%clk 0:00:47.722] } 18. gxf4 {[%clk 0:00:29.743] } Qg6+ {[%clk 0:00:46.431] } 19. Kh1 {[%clk 0:00:28.906] } Bxf2 {[%clk 0:00:45.18] } 20. Qxf2 {[%clk 0:00:27.389] } Qe4+ {[%clk 0:00:43.968] } 21. Kg1 {[%clk 0:00:23.422] } Qxe2 {[%clk 0:00:42.794] } 22. Qxe2 {[%clk 0:00:15.147] } Rxe2 {[%clk 0:00:41.657] } 23. Bd2 {[%clk 0:00:14.783] } Bc8 {[%clk 0:00:40.556] } 24. Bb4 {[%clk 0:00:14.727] } Rxf4 {[%clk 0:00:39.489] } 25. Nc3 {[%clk 0:00:13.647] } Rg4+ {[%clk 0:00:38.452] } 26. Kf1 {[%clk 0:00:12.015] } Rxh2 {[%clk 0:00:37.448] } 27. Rd1 {[%clk 0:00:11.92] } Rh1+ {[%clk 0:00:36.478] } 28. Ke2 {[%clk 0:00:11.7] } Rxd1 {[%clk 0:00:35.538] } 29. Nxd1 {[%clk 0:00:09.424] } h5 {[%clk 0:00:34.624] } 30. b3 {[%clk 0:00:09.033] } h4 {[%clk 0:00:33.742] } 31. Nf2 {[%clk 0:00:09.121] } Rg6 {[%clk 0:00:32.888] } 32. Bd2 {[%clk 0:00:08.734] } Kf8 {[%clk 0:00:32.061] } 33. Be3 {[%clk 0:00:08.139] } a5 {[%clk 0:00:31.259] } 34. Bf4 {[%clk 0:00:08.136] } a4 {[%clk 0:00:30.482] } 35. bxa4 {[%clk 0:00:08.148] } Ke7 {[%clk 0:00:29.73] } 36. c5 {[%clk 0:00:07.924] } Ke6 {[%clk 0:00:29.001] } 37. a5 {[%clk 0:00:05.861] } Kf5 {[%clk 0:00:28.295] } 38. Kf3 {[%clk 0:00:01.856] } Rg1 {[%clk 0:00:27.611] } 39. Bh2 {[%clk 0:00:01.604] } Rf1 {[%clk 0:00:26.948] } 40. Bd6 {[%clk 0:00:01.918] } Rc1 {[%clk 0:00:26.306] } 41. Ke3 {[%clk 0:00:02.261] } Rc4 {[%clk 0:00:25.684] } 42. Nd3 {[%clk 0:00:02.673] } g5 {[%clk 0:00:25.082] } 43. a3 {[%clk 0:00:02.082] } Re4+ {[%clk 0:00:24.495] } 44. Kf2 {[%clk 0:00:02.06] } h3 {[%clk 0:00:23.93] } 45. Nb4 {[%clk 0:00:01.313] } Rh4 {[%clk 0:00:23.382] } 46. Kg1 {[%clk 0:00:01.669] } Rg4+ {[%clk 0:00:22.852] } 47. Kh2 {[%clk 0:00:01.383] } Rc4 {[%clk 0:00:22.338] } 48. a6 {[%clk 0:00:01.653] } Rc3 {[%clk 0:00:21.837] } 49. a4 {[%clk 0:00:01.015] } Ra3 {[%clk 0:00:21.355] } 50. a7 {[%clk 0:00:01.036] } Rxa4 {[%clk 0:00:20.888] } 51. Nxc6 {[%clk 0:00:01.02] } Kf6 {[%clk 0:00:20.435] } 52. Be5+ {[%clk 0:00:01.019] } Ke6 {[%clk 0:00:19.997] } 53. Bd6 {[%clk 0:00:01.488] } Ra2+ {[%clk 0:00:19.572] } 54. Kg1 {[%clk 0:00:01.538] } g4 {[%clk 0:00:19.161] } 55. Bg3 {[%clk 0:00:01.941] } Ra4 {[%clk 0:00:18.762] } 56. Kh2 {[%clk 0:00:02.214] } Ra2+ {[%clk 0:00:18.376] } 57. Kg1 {[%clk 0:00:02.504] } Ra4 {[%clk 0:00:18.002] } 58. Kh2 {[%clk 0:00:02.423] } Ra2+ {[%clk 0:00:17.64] } 59. Kg1 {[%clk 0:00:01.02] } 1/2-1/2[/pgn]

Funny how Ember seems to always have something more important on it's mind than getting rid of the pawn on c7.

So far I'm estimating my Engines Elo at vaguely around 2500 so it should be a little weaker than Ember, maybe I should do a little tournament to get a better estimate.

[DreamerExx]

I had Ember 1.0.0 play against my engine for fun and the result was this game:

Funny how Ember seems to always have something more important on it's mind than getting rid of the pawn on c7.

So far I'm estimating my Engines Elo at vaguely around 2500 so it should be a little weaker than Ember, maybe I should do a little tournament to get a better estimate.

Honestly, it was a pretty weird game, haha, would you mind if I held a tournament of Ember vs. Erinn, 8+0.08, 100 games, and shared the results? I'm curious.

[DreamerExx]

I had Ember 1.0.0 play against my engine for fun and the result was this game:

Funny how Ember seems to always have something more important on it's mind than getting rid of the pawn on c7.

So far I'm estimating my Engines Elo at vaguely around 2500 so it should be a little weaker than Ember, maybe I should do a little tournament to get a better estimate.

I played an 8+0.08 tournament between Ember 1.0 and Erinn 1.0. The score was 52 wins, 24 draws, and 24 losses for Ember. Erinn plays well; I'd say his rating is around 2500-2600. But he has a very serious problem: he can lose on time in tight time controls. In my tournament, Erinn lost nine games on time (the position was already completely lost, but the fact of losing on time is not good). Here are the tournament's PGN:

[NichtElias]

Yeah, seems like I'll need to look into Erinn's time management a bit more. I'm usually testing at 1+0.05 and there I've noticed some losses on time as well, though to a lesser degree than what you found

[DreamerExx]

YO
[pgn][Event "Stockfish KILL"]
[Site "?"]
[Date "2026.06.20"]
[Round "4"]
[White "Stockfish 10"]
[Black "Ember"]
[Result "1/2-1/2"]
[ECO "C15"]
[GameDuration "00:00:23"]
[GameEndTime "2026-06-20T15:37:47.707 RTZ 2 (зима)"]
[GameStartTime "2026-06-20T15:37:24.456 RTZ 2 (зима)"]
[Opening "French"]
[PlyCount "94"]
[TimeControl "8+0.08"]
[Variation "Winawer (Nimzowitsch) variation"]

1. e4 {+1.03/17 0.59s} e6 {-0.08/1 0s} 2. d4 {+0.90/13 0.12s} d5 {-0.83/1 0s}
3. Nc3 {+0.71/16 0.46s} Bb4 {-0.79/1 0s} 4. exd5 {+0.68/15 0.059s}
exd5 {-0.78/1 0s} 5. Bd3 {+0.79/14 0.12s} c6 {-0.26/1 0s}
6. Nf3 {+1.10/11 0.038s} Nf6 {-0.58/10 0.33s} 7. Qe2+ {+1.04/12 0.11s}
Be7 {-0.48/11 0.32s} 8. O-O {+0.95/12 0.088s} O-O {-0.64/11 0.31s}
9. Re1 {+0.55/16 0.76s} Re8 {-0.07/10 0.31s} 10. Bf4 {+0.90/14 0.050s}
Bg4 {-0.33/8 0.30s} 11. Qe3 {+0.29/17 0.70s} Bh5 {-0.16/8 0.29s}
12. Ne5 {+0.79/13 0.097s} Nbd7 {-0.39/9 0.29s} 13. Qh3 {+0.75/14 0.095s}
Bg6 {-0.18/9 0.28s} 14. Nxg6 {+0.63/14 0.067s} hxg6 {+0.62/8 0.27s}
15. a4 {+0.62/14 0.080s} Nf8 {+0.36/9 0.27s} 16. a5 {+0.57/18 0.28s}
Bd6 {0.00/10 0.26s} 17. Rxe8 {+0.58/14 0.036s} Nxe8 {+0.04/12 0.26s}
18. Be3 {+0.76/15 0.053s} a6 {+1.02/11 0.25s} 19. Ne2 {+0.55/16 0.14s}
Bb4 {+1.27/12 0.24s} 20. Nc1 {-0.57/16 0.54s} Bxa5 {+1.74/12 0.24s}
21. Bf1 {-0.74/17 0.34s} Bc7 {+2.20/11 0.23s} 22. Nd3 {-0.96/16 0.11s}
Nf6 {+2.17/9 0.23s} 23. c3 {-0.66/15 0.12s} Bd6 {+2.18/10 0.23s}
24. g3 {-0.63/15 0.081s} a5 {+2.16/12 0.22s} 25. Qg2 {-0.69/16 0.42s}
a4 {+1.88/13 0.22s} 26. Qf3 {-0.70/15 0.070s} b5 {+1.96/8 0.21s}
27. h4 {-1.29/16 0.58s} Ne4 {+2.22/9 0.21s} 28. Bf4 {-1.37/13 0.070s}
Qf6 {+2.24/9 0.20s} 29. Qe3 {-1.11/16 0.13s} Bxf4 {+2.36/10 0.20s}
30. Qxf4 {-1.00/18 0.16s} Ne6 {+2.44/11 0.20s} 31. Qe3 {-0.47/15 0.13s}
g5 {+1.60/7 0.19s} 32. h5 {-0.72/18 0.38s} g4 {+1.64/7 0.19s}
33. Be2 {+0.25/15 0.14s} g6 {+0.74/8 0.19s} 34. Bxg4 {+0.51/15 0.12s}
gxh5 {+0.77/10 0.18s} 35. Bxh5 {+0.26/17 0.10s} Qf5 {+0.61/8 0.18s}
36. Qf3 {+0.27/19 0.13s} Qxf3 {+0.48/10 0.18s} 37. Bxf3 {+0.37/17 0.11s}
a3 {+0.33/8 0.17s} 38. Bg4 {+0.21/20 0.13s} Nd8 {+0.72/10 0.17s}
39. bxa3 {+0.19/17 0.083s} Kf8 {+0.88/10 0.17s} 40. f3 {0.00/19 0.28s}
Nxc3 {+0.64/10 0.17s} 41. Kf2 {0.00/18 0.042s} Ke7 {+1.20/9 0.16s}
42. Re1+ {0.00/17 0.19s} Kd6 {+0.21/9 0.16s} 43. Re8 {0.00/20 0.072s}
Kc7 {+0.21/8 0.16s} 44. Re7+ {0.00/21 0.094s} Kb6 {0.00/11 0.15s}
45. Re8 {0.00/22 0.062s} Kc7 {0.00/9 0.15s} 46. Re7+ {0.00/23 0.16s}
Kb6 {0.00/11 0.15s} 47. Re8 {0.00/24 0.12s}
Kc7 {0.00/10 0.15s, Draw by 3-fold repetition} 1/2-1/2[/pgn]