Andscacs - New version 0.62x

[cdani]

Hi!
I published a new version, 062x:

Changes
* Added knowledge of some basic endings KRBKR, KRNKR, KRKN, KQBKQ, KQNKQ, KBNKR, KBBKR, KNNKR, KBPKB.
* Added some knowledge about endings with bishops of different color.
* Bonus for grouped passed pawns.
* Diminish the evaluation if it’s nearer the 50 move draw rule.
* Augmented velocity of move generation and doing the moves.
* Diminished the possibilities of hash key collision, and fixed the validation of the hash move.
* Optimized a case where it was possible to maintain a move in the hash even if there was none.
* Limited the maximum number of extensions possible before qsearch.
* Fixed bugs in move generation and about storing in history.
* Move ordering:

• Favor attacking moves in some cases.
  Little penalization for pieces than return to previous square.
  Little penalization for king moves when there are many pieces.

* LMR, late move reductions:

• Reduce less if it’s an endgame.
  Reduce less if it’s in the firsts levels after root moves.

* Penalization for king too open.
* Moves found in hash than permit to return immediately, now are stored as killers and also update the history.
* Optimized the value about material ending that activates some reductions.

A comparative of gauntlets between the old and new version.

Old 062w:
50+.2 -67 of 2170

Code: Select all

Andscacs 0.62w1   - Atlas  3.60  x64         73.0 - 143.0    +42/=62/-112    33.80%
Andscacs 0.62w1   - Bobcat 3.25              79.0 - 141.0    +52/=54/-114    35.91%
Andscacs 0.62w1   - Naraku 1.4               40.5 - 181.5    +27/=27/-168    18.24%
Andscacs 0.62w1   - Nirvanachess             151.0 - 64.0    +129/=44/-42    70.23%
Andscacs 0.62w1   - Philou 3.7.1 64 bits     108.0 - 110.0    +79/=58/-81    49.54%
Andscacs 0.62w1   - RedQueen 1.1.97          79.0 - 139.0    +55/=48/-115    36.24%
Andscacs 0.62w1   - Rodent 0.15              114.0 - 100.0    +89/=50/-75    53.27%
Andscacs 0.62w1   - Spike 1.2 Turin          66.5 - 149.5    +42/=49/-125    30.79%
Andscacs 0.62w1   - The Baron 2.23           114.0 - 103.0    +92/=44/-81    52.53%
Andscacs 0.62w1   - cheng4 0.36c             49.5 - 164.5    +28/=43/-143    23.13%

New 062x:
50+.2 -22 of 1080

Code: Select all

Andscacs 0.62x   - Atlas  3.60  x64         46.5 - 61.5    +32/=29/-47    43.06%
Andscacs 0.62x   - Bobcat 3.25              49.0 - 61.0    +32/=34/-44    44.55%
Andscacs 0.62x   - Naraku 1.4               27.5 - 82.5    +21/=13/-76    25.00%
Andscacs 0.62x   - Nirvanachess             77.0 - 31.0    +66/=22/-20    71.30%
Andscacs 0.62x   - Philou 3.7.1 64 bits     55.0 - 53.0    +39/=32/-37    50.93%
Andscacs 0.62x   - RedQueen 1.1.97          51.5 - 56.5    +38/=27/-43    47.69%
Andscacs 0.62x   - Rodent 0.15              66.0 - 40.0    +48/=36/-22    62.26%
Andscacs 0.62x   - Spike 1.2 Turin          43.5 - 64.5    +30/=27/-51    40.28%
Andscacs 0.62x   - The Baron 2.23           62.0 - 46.0    +51/=22/-35    57.41%
Andscacs 0.62x   - cheng4 0.36c             27.5 - 78.5    +15/=25/-66    25.94%

Let's see what it's able to do

[PK]

can You provide a link, please?

[Graham Banks]

can You provide a link, please?

http://www.andscacs.com/andscacs062x.zip

[cdani]

Ok. Next time I will provide a direct link, a part of the link to the webpage.

I forget to mention that is clearly stronger on long time controls. So for example is able to obtain 55% instead of 43% against Atlas, or 43% instead of 25% against Naraku, or 38% instead of 26% against Cheng. I tell this without much testings.

[SzG]

Ok. Next time I will provide a direct link, a part of the link to the webpage.

I forget to mention that is clearly stronger on long time controls. So for example is able to obtain 55% instead of 43% against Atlas, or 43% instead of 25% against Naraku, or 38% instead of 26% against Cheng. I tell this without much testings.

Quite an achievement for a brand new engine.