New engine releases & news 2021

[amanjpro]

Just released Zahak 4.0

Can be downloaded here: https://github.com/amanjpro/zahak/releases/tag/4.0

Changes contain:

- King Safety, and Pawn Shield
- Pawn structure evaluation is redone, with various mis-evaluation fixes
- More aggressive Null Move Pruning
- NPS increase and performance optimizations (almost 40% more NPS)
- Add Internal Iterative Deepening
- Add Enhanced Futility Pruning
- Pseudo Legal Moves
- Fix SEE pruning
- Fix Hash-move and move ordering for pawn promotion
- Search Parameter tweaking

Strengith-wise I rate it around 2530-2570, I know this is a wide range, but my many tests show different results, and this is the average:

Code: Select all

Rank Name                          Elo     +/-   Games    Wins  Losses   Draws   Points   WWins  WLoss.  WDraws   BWins  BLoss.  BDraws 
   0 zahak_next                    -12      13    1600     448     501     651    773.5     246     212     342     202     289     309 
   1 nalwald-skylake  1.9           70      20     800     354     195     251    479.5     197      88     115     157     107     136 
   2 zahak_master                  -46      17     800     147     253     400    347.0      92     114     194      55     139     206 

ResultSet-EloRating>ratings
Rank Name        Rating   Δ     +    -     #     Σ    Σ%     W    L    D   W%    =%   OppR 
---------------------------------------------------------------------------------------------------------
   1 zahak_next   3136   0.0   11   11   800  484.0  60.5  369  201  230  46.1  28.8  3064 
   2 Loki3.5      3064  72.5   11   11   800  316.0  39.5  201  369  230  25.1  28.8  3136 
---------------------------------------------------------------------------------------------------------
  Δ = delta from the next higher rated opponent
  # = number of games played
  Σ = total score, 1 point for win, 1/2 point for draw

Score of zahak_next vs Barbarossa-0.6.0: 423 - 222 - 166  [0.624] 811
...      zahak_next playing White: 241 - 91 - 74  [0.685] 406
...      zahak_next playing Black: 182 - 131 - 92  [0.563] 405
...      White vs Black: 372 - 273 - 166  [0.561] 811
Elo difference: 87.9 +/- 21.8, LOS: 100.0 %, DrawRatio: 20.5 %

Score of zahak_next vs lozza 2: 145 - 53 - 87  [0.661] 285
...      zahak_next playing White: 83 - 18 - 42  [0.727] 143
...      zahak_next playing Black: 62 - 35 - 45  [0.595] 142
...      White vs Black: 118 - 80 - 87  [0.567] 285
Elo difference: 116.3 +/- 34.7, LOS: 100.0 %, DrawRatio: 30.5 %

Score of zahak_next vs zahak-darwin-amd64-3.0: 266 - 20 - 114  [0.807] 400
...      zahak_next playing White: 138 - 8 - 54  [0.825] 200
...      zahak_next playing Black: 128 - 12 - 60  [0.790] 200
...      White vs Black: 150 - 136 - 114  [0.517] 400
Elo difference: 249.1 +/- 31.9, LOS: 100.0 %, DrawRatio: 28.5 %
Finished match

Score of zahak_next vs Supernova_2.3_linux: 201 - 465 - 176  [0.343] 842
...      zahak_next playing White: 121 - 205 - 95  [0.400] 421
...      zahak_next playing Black: 80 - 260 - 81  [0.286] 421
...      White vs Black: 381 - 285 - 176  [0.557] 842
Elo difference: -112.7 +/- 21.7, LOS: 0.0 %, DrawRatio: 20.9 %

Score of zahak_next vs stash-19.0: 230 - 123 - 79  [0.624] 432
...      zahak_next playing White: 129 - 50 - 37  [0.683] 216
...      zahak_next playing Black: 101 - 73 - 42  [0.565] 216
...      White vs Black: 202 - 151 - 79  [0.559] 432
Elo difference: 87.9 +/- 30.4, LOS: 100.0 %, DrawRatio: 18.3 %

The tests show that:

Zahak 4.0 is:
- +72 elo points stronger than Loki 3.5 (rated 2495 in 40/15 CCRL)
- +87 elo points against Barbarossa 0.6.0 (rated 2495)
- +87 elo points against Stash 19 (rated 2495 again)
- +249 against Zahak 3.0 (rated 2407) (which I believe is an exaggeration)
- +116 against Lozza 2 somehow (even though it is rated 2560)
- -112 against Supernova 2.3 (rated 2650)
- -70 against Nalwald 1.9 (expected to be around 2630)

So yeah, I fail to guess a better range, sorry

P.S. All matches are 400 games or more

I also published an article about this release and ZaTour season 2 here: https://zahak.amanj.me/posts/zahak-version-4.0/

[Rebel]

Just released Zahak 4.0

Zahak 4.0 running for the GRL.

1600 games

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

Keep your fingers crossed.

[amanjpro]

Just released Zahak 4.0

Zahak 4.0 running for the GRL.

1600 games

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

Keep your fingers crossed.

Thanks a lot Ed, so far a good start, but too early to tell

[lithander]

Just released Zahak 4.0

Congratulations! Your fast progress is really impressive. Version 1 was only released a 3 months ago, right?

I have been using Zahak 1 and Zahak 2 in my own gauntlets to test MMC and they have been stable and flawlass sparring partners in thousands of games. And I also like how you're creating a whole ecosystem around your engine. The Zatour website, the blog... it's really adding a lot to my fun with chess programming! Thanks

[Gabor Szots]

Thank you Amanj. Tournament in progress.

[amanjpro]

Thank you Amanj. Tournament in progress.

Great news, thank you a lot Gabor

Just released Zahak 4.0

Congratulations! Your fast progress is really impressive. Version 1 was only released a 3 months ago, right?

I have been using Zahak 1 and Zahak 2 in my own gauntlets to test MMC and they have been stable and flawlass sparring partners in thousands of games. And I also like how you're creating a whole ecosystem around your engine. The Zatour website, the blog... it's really adding a lot to my fun with chess programming! Thanks

Thanks for your nice words. There is no secret behind my fast progress, we have been in lockdown+curfew for the last year or so...

[amanjpro]

Just released Zahak 4.0

Zahak 4.0 running for the GRL.

1600 games

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

Keep your fingers crossed.

The gauntlet is done, and the gain is 144 Elo points, I so wanted it to be above 150 , but a good progress nevertheless... Thank you for testing it again

[Rebel]

Just released Zahak 4.0

Zahak 4.0 running for the GRL.

1600 games

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

Keep your fingers crossed.

Thanks a lot Ed, so far a good start, but too early to tell

Code: Select all

Gambit Rating List
Running      : Gauntlet Zahak 4.0 
Time Control : Time control 40/120
Games        : 1600

Results from file gauntlet-zahak.pgn:

No. Name           Win Draw Loss Unf.  Score Games       %
----------------------------------------------------------
  1 Zahak 4.0     +828 =355 -417   *0 1005.5  1600   62.8%
  2 Jumbo 0.6.10   +63  =49  -88   *0   87.5   200   43.8%
  3 Monolith 0.3   +53  =66  -81   *0   86.0   200   43.0%
  4 Foxsee 7.20.1  +55  =52  -93   *0   81.0   200   40.5%
  5 CT800 1.42     +60  =32 -108   *0   76.0   200   38.0%
  6 Jumbo 0.5.3    +58  =36 -106   *0   76.0   200   38.0%
  7 Orion 04       +47  =47 -106   *0   70.5   200   35.2%
  8 Foxsee 7.8     +44  =39 -117   *0   63.5   200   31.8%
  9 Orion 03       +37  =34 -129   *0   54.0   200   27.0%

Total Games:    1600
White Wins:      597 (37.3%)
Black Wins:      648 (40.5%)
Draws:           355 (22.2%)
Unfinished:        0 (0.0%)

Estimated elo gain for Zahak_4.0
Elo pool : 2439
Zahak 3.0 : 2378.0
Zahak_4.0 : 2522.0
Difference : 144.0

+144

Outstanding !

[Terje]

Weiss 1.4 released.

Beats 1.3 by about 160 elo in my testing, but I expect some less in rating lists.

[CMCanavessi]

Weiss 1.4 released.

Beats 1.3 by about 160 elo in my testing, but I expect some less in rating lists.

Does Weiss support 960?