pawn definitions in Gull

[outAtime]

Could someone please explain what are these pawn types in Gull?

1. PawnUp
2. PawnUR
3. PawnWeak

I have tried again and again to read the code but I just cant understand what these pawns are. How would they be defined? I know there are also doubled pawns and isolated pawns, those are simple enough, and I have seen some other programs with weak pawns, but Im not sure what is a weak pawn to Gull. Ive never seen 1. or 2. anywhere else. Thanks.

[Edsel Apostol]

Could someone please explain what are these pawn types in Gull?

1. PawnUp
2. PawnUR
3. PawnWeak

I have tried again and again to read the code but I just cant understand what these pawns are. How would they be defined? I know there are also doubled pawns and isolated pawns, those are simple enough, and I have seen some other programs with weak pawns, but Im not sure what is a weak pawn to Gull. Ive never seen 1. or 2. anywhere else. Thanks.

It's some kind of a backwards pawn computation.

Here's the explanation for black pawns if I've read it correctly:

Code: Select all

		if (not supported by own pawn (chain)) {
			score += PawnUP[rank];
			if (not supportable by pawn push of own pawn) score += PawnUR[rank];
			else {
			    for (pawn pushes that is capable of supporting)
					if (not blocked by other pawns in its way to support) goto weak_b;
				score += PawnUR[rank];
			}
			weak_b:
			if (there's any pawn in the front square || (the front square is attacked by enemy pawn and not attacked by allied pawn) {
				score += PawnWeak[rank];
				if (there is no other pawn in front upto promotion square (in an open file)) score += PawnWeakOp[rank];
			}
		}

[Dann Corbit]

Could someone please explain what are these pawn types in Gull?

1. PawnUp
2. PawnUR
3. PawnWeak

I have tried again and again to read the code but I just cant understand what these pawns are. How would they be defined? I know there are also doubled pawns and isolated pawns, those are simple enough, and I have seen some other programs with weak pawns, but Im not sure what is a weak pawn to Gull. Ive never seen 1. or 2. anywhere else. Thanks.

PawnUp just resolves to a number and the name is used because of the archane score evaluation numbers.

Code: Select all

            score += PawnUP;

becomes:

Code: Select all

            score += ((5) + ((5) << 16)); //327685

PawnWeak resolves to the following table of 8 numbers:

Code: Select all

const int       PawnWeak[8] =
{
    0, ((15) + ((10) << 16)), ((10) + ((5) << 16)), ((7) + ((4) << 16)), ((10) + ((5) << 16)), ((12) + ((6) << 16)), 0, 0
};

I did not see PawnUR