Zevra 1.6.2 r536

[sovaz1997]

New versions of Zevra (v1.7):
https://github.com/sovaz1997/Zevra/rele ... /v1.7_r560
+100 ELO points

[sovaz1997]

Fix bugs:

https://github.com/sovaz1997/Zevra/rele ... 1.7.1_r563

[BrendanJNorman]

Fix bugs:

https://github.com/sovaz1997/Zevra/rele ... 1.7.1_r563

Thanks Oleg, this is a cool engine, probably around 2100-2150 Elo (FIDE Elo not CCRL).

I played a blitz game against it and was positionally crushing it, but lost on time in a complicated pawn up endgame.

The final position was better for me, but getting more complicated due to an inaccuracy on my part.

I feel like I'm stronger than Zevra, but still need to work in order to beat it.

A nice sparring partner for humans - good work my friend.

Brendan

[sovaz1997]

Thank you for testing!

[Gerd Isenberg]

Hi Oleg,

your code looks like from an obfuscation contest or compiler optimization test - a violation of using bitboards

One sample of many:

Code: Select all

uint64_t possibleMoves, mask, emask;
uint8_t color;
if(currentState.whiteMove) {
  color = WHITE;
  mask = currentState.white_bit_mask;
  emask = currentState.black_bit_mask;
} else {
  color = BLACK;
  mask = currentState.black_bit_mask;
  emask = currentState.white_bit_mask;
}

possibleMoves = rookMagic[pos / 8][pos % 8]. 
 getPossibleMoves( rookMagicMask[pos / 8][pos % 8] 
       & (currentState.white_bit_mask | currentState.black_bit_mask)  
       & (UINT64_MAX ^ vec1_cells[pos])) // occupancy of from square should not care
  & ((currentState.figures[KING] ^ emask) ^ UINT64_MAX)   // exclude king captures
  & (UINT64_MAX ^ emask)                                  // exclude captures
  & (mask ^ UINT64_MAX);                                  // exclude capturing own pieces

Better use one dimensional board arrays, no branch on currentState.whiteMove but array access, and remove redundancies ...
If encapsulating rook magics as object for each square, it may also contain not only magic factor and shift but also the rook/bishop mask (and don't call the method getPossibleMoves but getControls, getAttacks or getTargets):

Code: Select all

  color = currentState.whiteMove;
  omask = currentState.piece_bit_mask[color];
  emask = currentState.piece_bit_mask[color^1];
  occu  = omask & emask;

  possibleMoves = rookMagic[pos].getTargets(occu) & ~occu; // only quite moves

Best regards,
Gerd

[sovaz1997]

Release Zevra v1.8 r583:
https://github.com/sovaz1997/Zevra/rele ... /v1.8_r583

Code: Select all

tc=10+0.1 Hash=16

Score of Zevra 20180123 vs Zevra v1.7.1 r563: 869 - 240 - 191  [0.742] 1300
Elo difference: 183.44 +/- 19.41
---------------------------------------------------------------------------
tc=60+0.6 Hash=16

Score of Zevra 20180123 vs Zevra v1.7.1 r563: 707 - 227 - 241  [0.704] 1175
Elo difference: 150.73 +/- 18.90

Just now I saw your message. I'll try to fix it in the next version. Thank you.

[BrendanJNorman]

Release Zevra v1.8 r583:
https://github.com/sovaz1997/Zevra/rele ... /v1.8_r583

Code: Select all

tc=10+0.1 Hash=16

Score of Zevra 20180123 vs Zevra v1.7.1 r563: 869 - 240 - 191  [0.742] 1300
Elo difference: 183.44 +/- 19.41
---------------------------------------------------------------------------
tc=60+0.6 Hash=16

Score of Zevra 20180123 vs Zevra v1.7.1 r563: 707 - 227 - 241  [0.704] 1175
Elo difference: 150.73 +/- 18.90

Just now I saw your message. I'll try to fix it in the next version. Thank you.

Very quick to release a new version Oleg...

What are the changes?

[sovaz1997]

I added a mobility bonus and improved the security of the king (the main things that gave such a gain in the power of the game)

[CMCanavessi]

I added a mobility bonus and improved the security of the king (the main things that gave such a gain in the power of the game)

That was a huge increase in strenght! Very nice.

Can we expect a 1.8.1 version soon (as you usually do) or you're confident this is stable enough and bug-free?

[sovaz1997]

I added a mobility bonus and improved the security of the king (the main things that gave such a gain in the power of the game)

That was a huge increase in strenght! Very nice.

Can we expect a 1.8.1 version soon (as you usually do) or you're confident this is stable enough and bug-free?

This version is much more stable than version 1.7. I plan to make some optimizations to the moves generator in version 1.8.1. Thank you!