Koivisto 7.0

[Luecx]

Koivisto 7.0
Howdy fellow chess enthusiasts,

It's been a while since we released 6.0, but now it's finally time for another release. Just a few days ago we passed the usual 100 stc self-play Elo we aim for for every release. Most of the gains come from search patches, although the embedded network is also significantly stronger.

This milestone also marks the end of simplistic neural network architectures inside Koivisto. More complex architectures are planned and there may even be neural networks used apart from evaluation. We have a number of ideas, and we look forward to seeing their results inside Koivisto.

```
STC:
ELO | 107.31 +- 3.91 (95%)
CONF | 8.0+0.08s Threads=1 Hash=8MB
GAMES | N: 13120 W: 4896 L: 968 D: 7256

LTC:
ELO | 89.39 +- 4.86 (95%)
CONF | 60.0+0.60s Threads=1 Hash=8MB
GAMES | N: 6256 W: 1857 L: 282 D: 4117
```

Koivisto 7.0 will play in the upcoming TCEC swizz.
Compiles for Windows and Linux can be found on our github page.

With love,
Finny & Kimmy

[CMCanavessi]

Incredible progress!

[Archimedes]

Koivisto 7.0 for Android:
https://app.box.com/s/bebtvgxzqmy6rcvxmx0o29wi7d42m40s

[matejst]

Thank you! And wish you both a lot of success -- and not only with the further development of your engine!

There is a vibrant community around OpenBench and several engines are improving tremendously lately.

[Luecx]

Thank you! And wish you both a lot of success -- and not only with the further development of your engine!

There is a vibrant community around OpenBench and several engines are improving tremendously lately.

Thanks a lot! You are right, there seem to be certain hotspots of development lately. Having the computational needs is fundamental for effective development. Having a clever community which shares ideas across each other (namely on the OB discord, Koivisto discord, etc.) is probably a big part of this

[Damir]

Amazing progress. Thanks a lot for your effort in improving your engine.

[Rebel]

Koivisto 7.0
Howdy fellow chess enthusiasts,

It's been a while since we released 6.0, but now it's finally time for another release. Just a few days ago we passed the usual 100 stc self-play Elo we aim for for every release. Most of the gains come from search patches, although the embedded network is also significantly stronger.

....

You keep on surprising us.

For the GRL -

Games : 2400

Elo pool : 3480

http://rebel13.nl/a/grl.htm

I am using the AVX2 version but I noticed there hardly is any difference in speed in comparison with the SSE2 version. The same counts for Stockfish and Komodo. It seems that some profit and others don't, or that it is a matter of engineering, or that AVX2 is overrated. Maybe you can shed some light on the matter.

[matejst]

I played a short match between Koivisto and SlowChess at 1'+1", using Frank Quisinsky's Feobos opening book. The result was 9,5-6,5 for SlowChess, and while the result is obviously not very important, what was obvious is that the endgame net SC uses gives it a huge advantage in balanced positions. In the last game, e.g., there was a very long combination which ended in a pawn endgame -- SC immediately knew it was won, while K. did not. Watching the games, time and time again K. had a pawn more, better pawns in the ending, but still SC managed draw.

I think that gambit line that Ed uses for the GRL will be better for Koivisto than the balanced openings I chose for this testing, but, nonetheless, endings are a point that can be improved. I give here the game with the queen sac and the resulting lost pawn endgame.


[pgn]
[Event "1 Minutes/Game + 1 Seconds/Move"]
[Site "Engine Match"]
[Date "2021.10.31"]
[Round "10"]
[White "SlowChess Blitz 2.7"]
[Black "Koivisto 7.0"]
[Result "1-0"]

1. c4 {book 0s} Nc6 {book 0s} 2. d4 {book 0s} d5 {book 0s}
3. Nc3 {book 0s} e6 {book 0s} 4. Nf3 {book 0s} Bb4 {book
0s} 5. e3 {book 0s} Nf6 {book 0s} 6. Bd3 {book 0s} O-O
{book 0s} 7. O-O {book 0s} dxc4 {book 0s} 8. Bxc4 {book 0s}
Bd6 {book 0s} 9. e4 {book 0s} e5 {book 0s} 10. d5 {+0.52/17
3s} Ne7 {+0.92/18 2s} 11. h3 {+0.40/16 2s} Ng6 {+1.22/19
6s} 12. Be3 {+0.36/17 4s} Nh5 {+0.86/18 2s (Bd7)} 13. Re1
{+0.72/16 2s} Nhf4 {+0.75/19 2s} 14. Bf1 {+0.56/15 2s} f5
{+0.52/17 3s} 15. Rc1 {+0.72/17 3s} fxe4 {+1.25/18 5s
(Qe7)} 16. Nxe4 {+0.80/16 3s} b6 {+0.89/18 3s (Qe7)} 17. a3
{+0.76/15 2s} h6 {+0.88/16 2s (Bf5)} 18. Kh2 {+0.92/15 5s}
Bb7 {+1.06/19 2s} 19. Bxf4 {+0.88/18 2s} Rxf4 {+0.94/19 1s
(Nxf4)} 20. Bb5 {+0.88/17 2s} Qe7 {+0.97/18 3s} 21. Bc6
{+0.92/16 2s} Bxc6 {+1.05/18 2s} 22. dxc6 {+0.96/16 2s} Qe6
{+1.17/19 2s (Rd8)} 23. Rc3 {+0.92/17 2s} Rf7 {+1.05/18 2s
(Rd8)} 24. Qc2 {+0.88/17 2s} Nf4 {+1.11/19 2s (Raf8)}
25. Rd1 {+0.80/15 2s} Rd8 {+1.18/19 4s} 26. Re3 {+0.76/16
4s} Be7 {+1.23/19 2s} 27. Rxd8+ {+0.92/15 0s} Bxd8
{+1.26/19 1s} 28. b4 {+0.72/16 5s} Be7 {+1.12/19 1s}
29. Qb2 {+0.96/16 2s} Nd5 {+1.36/21 2s (Bf6)} 30. Qb3
{+1.84/16 1s} Qxc6 {+0.77/19 0s (Rf8)} 31. Rd3 {+1.08/18
6s} Nf4 {+1.42/24 1s} 32. Nxe5 {+1.38/16 1s} Qxe4 {+2.08/23
2s} 33. Qxf7+ {+1.88/14 0s} Kh7 {+1.86/22 1s} 34. Rf3
{+1.40/16 7s} Qxe5 {+1.63/23 0s} 35. Rxf4 {+0.56/13 0s}
Qxf4+ {+1.90/22 2s} 36. Qxf4 {+0.64/13 1s} Bd6 {+1.71/22
0s} 37. Qxd6 {+2.29/14 6s} cxd6 {+0.80/20 0s} 38. Kg3
{+2.48/14 1s} Kg6 {+0.60/21 1s} 39. Kf4 {+2.88/15 5s} Kf6
{+0.72/21 0s} 40. Ke4 {+2.76/13 1s} Ke6 {+0.92/21 1s}
41. f4 {+3.16/13 1s} d5+ {+1.63/21 4s (g6)} 42. Ke3
{+3.59/14 1s} b5 {+1.54/19 2s (h5)} 43. g3 {+5.04/13 0s}
Kf6 {+2.60/21 2s (Kf5)} 44. Kd4 {+3.52/15 1s} Ke6 {+4.40/20
2s} 45. Kc5 {+5.76/14 1s} h5 {+2.26/18 1s (a6)} 46. g4
{+8.01/15 1s} g6 {+5.42/20 2s} 47. Kd4 {+5.53/15 1s} h4
{+6.15/19 1s} 48. Kc5 {+10.24/16 1s} 1-0
[/pgn]

[matejst]

I am using the AVX2 version but I noticed there hardly is any difference in speed in comparison with the SSE2 version. The same counts for Stockfish and Komodo. It seems that some profit and others don't, or that it is a matter of engineering, or that AVX2 is overrated. Maybe you can shed some light on the matter.

I tried the sse2 and Ipman's popcount and ssse4 versions -- no differences, so I stuck with the original engine.

[Luecx]

I played a short match between Koivisto and SlowChess at 1'+1", using Frank Quisinsky's Feobos opening book. The result was 9,5-6,5 for SlowChess, and while the result is obviously not very important, what was obvious is that the endgame net SC uses gives it a huge advantage in balanced positions. In the last game, e.g., there was a very long combination which ended in a pawn endgame -- SC immediately knew it was won, while K. did not. Watching the games, time and time again K. had a pawn more, better pawns in the ending, but still SC managed draw.

I think that gambit line that Ed uses for the GRL will be better for Koivisto than the balanced openings I chose for this testing, but, nonetheless, endings are a point that can be improved. I give here the game with the queen sac and the resulting lost pawn endgame.


[pgn]
[Event "1 Minutes/Game + 1 Seconds/Move"]
[Site "Engine Match"]
[Date "2021.10.31"]
[Round "10"]
[White "SlowChess Blitz 2.7"]
[Black "Koivisto 7.0"]
[Result "1-0"]

1. c4 {book 0s} Nc6 {book 0s} 2. d4 {book 0s} d5 {book 0s}
3. Nc3 {book 0s} e6 {book 0s} 4. Nf3 {book 0s} Bb4 {book
0s} 5. e3 {book 0s} Nf6 {book 0s} 6. Bd3 {book 0s} O-O
{book 0s} 7. O-O {book 0s} dxc4 {book 0s} 8. Bxc4 {book 0s}
Bd6 {book 0s} 9. e4 {book 0s} e5 {book 0s} 10. d5 {+0.52/17
3s} Ne7 {+0.92/18 2s} 11. h3 {+0.40/16 2s} Ng6 {+1.22/19
6s} 12. Be3 {+0.36/17 4s} Nh5 {+0.86/18 2s (Bd7)} 13. Re1
{+0.72/16 2s} Nhf4 {+0.75/19 2s} 14. Bf1 {+0.56/15 2s} f5
{+0.52/17 3s} 15. Rc1 {+0.72/17 3s} fxe4 {+1.25/18 5s
(Qe7)} 16. Nxe4 {+0.80/16 3s} b6 {+0.89/18 3s (Qe7)} 17. a3
{+0.76/15 2s} h6 {+0.88/16 2s (Bf5)} 18. Kh2 {+0.92/15 5s}
Bb7 {+1.06/19 2s} 19. Bxf4 {+0.88/18 2s} Rxf4 {+0.94/19 1s
(Nxf4)} 20. Bb5 {+0.88/17 2s} Qe7 {+0.97/18 3s} 21. Bc6
{+0.92/16 2s} Bxc6 {+1.05/18 2s} 22. dxc6 {+0.96/16 2s} Qe6
{+1.17/19 2s (Rd8)} 23. Rc3 {+0.92/17 2s} Rf7 {+1.05/18 2s
(Rd8)} 24. Qc2 {+0.88/17 2s} Nf4 {+1.11/19 2s (Raf8)}
25. Rd1 {+0.80/15 2s} Rd8 {+1.18/19 4s} 26. Re3 {+0.76/16
4s} Be7 {+1.23/19 2s} 27. Rxd8+ {+0.92/15 0s} Bxd8
{+1.26/19 1s} 28. b4 {+0.72/16 5s} Be7 {+1.12/19 1s}
29. Qb2 {+0.96/16 2s} Nd5 {+1.36/21 2s (Bf6)} 30. Qb3
{+1.84/16 1s} Qxc6 {+0.77/19 0s (Rf8)} 31. Rd3 {+1.08/18
6s} Nf4 {+1.42/24 1s} 32. Nxe5 {+1.38/16 1s} Qxe4 {+2.08/23
2s} 33. Qxf7+ {+1.88/14 0s} Kh7 {+1.86/22 1s} 34. Rf3
{+1.40/16 7s} Qxe5 {+1.63/23 0s} 35. Rxf4 {+0.56/13 0s}
Qxf4+ {+1.90/22 2s} 36. Qxf4 {+0.64/13 1s} Bd6 {+1.71/22
0s} 37. Qxd6 {+2.29/14 6s} cxd6 {+0.80/20 0s} 38. Kg3
{+2.48/14 1s} Kg6 {+0.60/21 1s} 39. Kf4 {+2.88/15 5s} Kf6
{+0.72/21 0s} 40. Ke4 {+2.76/13 1s} Ke6 {+0.92/21 1s}
41. f4 {+3.16/13 1s} d5+ {+1.63/21 4s (g6)} 42. Ke3
{+3.59/14 1s} b5 {+1.54/19 2s (h5)} 43. g3 {+5.04/13 0s}
Kf6 {+2.60/21 2s (Kf5)} 44. Kd4 {+3.52/15 1s} Ke6 {+4.40/20
2s} 45. Kc5 {+5.76/14 1s} h5 {+2.26/18 1s (a6)} 46. g4
{+8.01/15 1s} g6 {+5.42/20 2s} 47. Kd4 {+5.53/15 1s} h4
{+6.15/19 1s} 48. Kc5 {+10.24/16 1s} 1-0
[/pgn]

Thank you very much We will investigate!