Ethereal 8.62 64-bit Gauntlet for CCRL 40/40

[Graham Banks]

PGN - http://kirill-kryukov.com/chess/discuss ... p?id=41141

[Graham Banks]

Code: Select all

CCRL 40/40 Rating List - Custom engine selection
783129 games played by 2026 programs, run by 21 testers
Ponder off, General books (up to 12 moves), 3-4-5 piece EGTB
Time control: Equivalent to 40 moves in 40 minutes on Athlon 64 X2 4600+ (2.4 GHz), about 15 minutes on a modern Intel CPU.
Computed on January 20, 2018 with Bayeselo based on 783'129 games
Tested by CCRL team, 2005-2018, http://computerchess.org.uk/ccrl/4040/

Rank               Engine                Elo   +    -   Score  AvOp  Games
1 Ethereal 8.62 64-bit               2879  +28  -28  49.9%   +0.9   399
  Ethereal 8.37 64-bit               2822  +30  -30  54.7%  -31.9   360
  Ethereal 8.28 64-bit               2747  +29  -29  48.9%   +4.6   371
  Ethereal 8.19 64-bit               2688  +26  -26  56.0%  -38.9   484
  Ethereal 8.02 64-bit               2618  +32  -32  52.0%  -15.1   343
  Ethereal 8.12 64-bit               2609  +26  -26  51.9%  -11.9   509
  Ethereal 8.05 64-bit               2593  +30  -30  45.3%  +31.8   374
  Ethereal 7.78 64-bit               2587  +25  -25  52.9%  -19.6   543
  Ethereal 7.70 64-bit               2509  +31  -31  47.1%  +15.3   365

[D Sceviour]

In less than two years, Andrew Grant's original Ethereal engine as improved 400 elo. At that rate, Ethereal will be giving Stockfish a run for its money soon.
Andrew is a very gifted C programmer. He usually seems to hit on the correct algorithm. A recent interesting idea was the introduction of a double attack bitboard, which is finding new uses in selective searching.

[AndrewGrant]

Thank you for the kind words.

I think the double attack bitboard for pruning is just a very poor mans SEE.

Did you find any success with it in Schooner?

[D Sceviour]

Thank you for the kind words.

I think the double attack bitboard for pruning is just a very poor mans SEE.

Did you find any success with it in Schooner?

Currently, a double attack is used for reducing/increasing checking extensions, and a Quiescent SEE prune. Undoubtedly, there will be other applications when the opportunity arises to include it. There are new possibilities for king safety and static evaluations. It seems with hundreds of lines to look at, it can take months to get around to re-testing all of them.