Doubled and Backward Pawn Engine "Definitions"

[brianr]

Been working on pawn eval for Tinker for some time and was wondering about a couple of definitions.

Backwards:
Do you count as backwards a pawn on its starting position home rank?
Does the stop square have to be not controlled by the opponent?
Or both stop squares, when applicable?
But not if passed?

Doubled:
There are many definitions, and in some cases they may even be "good" (as in not isolated and lead pawn supported and some center influence).

My questions involve the ranks between doubled pawns.
One can perhaps minimally only count doubled pawns on adjacent ranks,
or those with just empty ranks,
or with just its own pieces in between,
or the opponent's,
or various combinations.

Initital testing with Tinker (which has some cummulative and potentially hefty doubled pawn penalties) indicates that it plays better when only counting doubled pawns on adjacent ranks.

So, just wondering what other have found.
Thanks,
Brian

Some links:

http://home.comcast.net/~danheisman/Art ... _pawns.htm

http://en.wikipedia.org/wiki/Chess_piece_relative_value

http://chessprogramming.wikispaces.com/Doubled+Pawn

[Ron Murawski]

I have never been very successful scoring backwards or doubled pawns. What seems to work is identifying weak pawns, which I define as those without a pawn beside it (phalanx) or without another pawn protecting it. There are degrees of weakness, for instance if the weak pawn is on a semi-open file and the opponent has all major pieces, then this is very bad.

Ron

[Sven]

Duplicate thread, Ron's answer should be moved into the other thread IMO.

Sven