open files and diagonals

[flok]

Hi,

STS says that Micah could be improved regarding "Open Files and Diagonals".
Now someone told me that an open file in this case means a file without any pawns on it, not neccessarily any other piece-type (correct?). Is the same true for the diagonals?

In old code I found a check for files without pawns on it but with rooks on it, that was worth 15 points. Shouldn't that be rooks & queens?
And is it the same for open diagonals with bishops and queens? or only bishops?

[chrisw]

Hi,

STS says that Micah could be improved regarding "Open Files and Diagonals".
Now someone told me that an open file in this case means a file without any pawns on it, not neccessarily any other piece-type (correct?). Is the same true for the diagonals?

In old code I found a check for files without pawns on it but with rooks on it, that was worth 15 points. Shouldn't that be rooks & queens?
And is it the same for open diagonals with bishops and queens? or only bishops?

Who knows what should and shouldn't be. You need to game test your version to find out.

An open file is one with no pawns on it. A rook on an open file normally gets a bonus. It's probably better to omit doing the same with the queen.

You could argue that a file with no pawns, but with a (pawn) protected minor piece on it, is no longer an open file for the side without the minor piece.

Rybka had a unique feature that pawns behind a rook didn't count. And later Rybkas introduced the also unique protected minor piece on open file cancelled out the openfile-ness.

Diagonals are another thing. There are 28? diagonals, as opposed to 8 files, so it's a lot of work, some are more important than others, and, if you control one open diagonal, your opponent has a lot of other choices. Possibly more trouble than it's worth.