New engine releases & news 2021

[WinPooh]

GreKo 2021.06 MP - multithreaded version:
http://greko.su/greko-2021.06.MP.zip

[Damir]

Thanks for the new Greko Vladimir. Unfortunately I don't see any Threads option in Greko params. There is only a Hash option... Are you sure it is supporting MP ?

[tmokonen]

I don't know if he re-uploaded or not, but I see a Threads option here (up to 4 threads).

[WinPooh]

Thanks for the new Greko Vladimir. Unfortunately I don't see any Threads option in Greko params. There is only a Hash option... Are you sure it is supporting MP ?

Do you see "Threads" option in reply to "uci" command in console mode?
It should look like this:

Code: Select all

GreKo 2021.06 MP (30-June-2021)

White(1): uci
id name GreKo 2021.06 MP
id author Vladimir Medvedev
option name Hash type spin default 128 min 1 max 4096
option name Strength type spin default 100 min 0 max 100
option name Threads type spin default 1 min 1 max 4
uciok

[Damir]

Yes Now I see it. Greko only supports 4 threads ?

[Damir]

Also tried it in Infinity GUI and it showed no Threads param... is nothing surprising as always when it comes to that GUI...

Fritz GUI is miles ahead of it.

[Damir]

And now the engine stopped responding when trying and play a game in Infinity GUI after 7 moves... was about to run out of time. Was trying it whitout a book.. In Fritz GUI it play with no problems with a book.

[WinPooh]

Also tried it in Infinity GUI and it showed no Threads param... is nothing surprising as always when it comes to that GUI...

Never tested with this GUI.
In Arena, Winboard/XBoard and Cutechess-Cli it works OK.
Yes, currently only 4 threads are supported.
Number of nodes is reported only for the main thread.

[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.