Stockfish: crazyhouse idea: empty 7th/8th rank

[isaacl]

Pawn drops on 7th rank are damaging, perhaps stockfish should include this idea in evals.

[ianfab]

As soon as a pawn is dropped on the seventh rank, the passed pawn bonus takes account of it, but I agree that it might help to add an anticipatory malus for holes on the seventh rank, since the pawn drop can also serve as a threat without necessarily being executed.

[isaacl]

Right, opening up a hole on the 7th rank is a useful long term positional gain, even if stockfish can't see a direct line with a pawn drop on the square.

[ddugovic]

Also queen or rook drops, and sometimes knight drops, tend to be quite strong.

[isaacl]

actually drops of any type on any square is usually at least somewhat beneficial :-)

[ppigazzini]

The search should already account for:

• the hole and the pawn drop
• to drop or to keep in hand (have some pieces in hand is usually somewhat beneficial)

[ianfab]

I have started a first test for a very simple implementation of this idea (http://35.161.250.236:6543/tests/view/58c5826a6e23db7956a14344) so that we will have some data as an input for this discussion.

[ianfab]

Second try: http://35.161.250.236:6543/tests/view/58e178146e23db2fa8080f48. Only add bonus if the pawn can move (advance or capture) from the square on 7th rank.

[ddugovic]

I too made an attempt at this idea: http://35.161.250.236:6543/tests/view/58e2ed386e23db2fa8080faa

[ddugovic]

Can anyone share a test position where SF misplayed due to not seeing this idea?