Pawn table wise

[Henk]

According to Nimzowitsch a passed pawn is only dangerous if it is not blocked. So that means a pawn table can not be used to evaluate a passed pawn. Or should it contain information that tells whether passed pawn is blocked or not ?

[Sven]

According to Nimzowitsch a passed pawn is only dangerous if it is not blocked. So that means a pawn table can not be used to evaluate a passed pawn. Or should it contain information that tells whether passed pawn is blocked or not ?

Being blocked or not is only one of several properties of a position related to passed pawns that needs more information than just the location of pawns. Other properties include location of kings (e.g. is it an outside passer?), existence of enemy pieces, etc. So you are right, passed pawn evaluation is usually not possible solely based on information from a pawn hash table, even if such tables sometimes include king locations as well.

[Karlo Bala]

According to Nimzowitsch a passed pawn is only dangerous if it is not blocked. So that means a pawn table can not be used to evaluate a passed pawn. Or should it contain information that tells whether passed pawn is blocked or not ?

IMO, passed pawns are stronger when queens and other pieces are on the table, because they keep opponent king far away. Defended passed pawns are strong always.

[BeyondCritics]

IMO, passed pawns are stronger when queens and other pieces are on the table, because they keep opponent king far away. Defended passed pawns are strong always.

Did you actually mean passed pawns are stronger when queens and other pieces are not on the table, because they keep opponent king far away?

In any case, passer gain considerable in strength in the endgame, thats for sure.

[Karlo Bala]

IMO, passed pawns are stronger when queens and other pieces are on the table, because they keep opponent king far away. Defended passed pawns are strong always.

Did you actually mean passed pawns are stronger when queens and other pieces are not on the table, because they keep opponent king far away?

In any case, passer gain considerable in strength in the endgame, thats for sure.

If a passed pawn is well defended by a pawn, then we can exchange all pieces and win pawn ending, but if a passed pawn isn't defended than it is not so simple. A passed pawn can easily become a weak pawn. Minor pieces are good in maintaining the blockade, so it is often a good idea to trade some minor pieces. If we trade all pieces and opponent’s king are closer to the passer, than the passer will fall (engines sometimes can't see that due to horizon effect). Major pieces are not good blockers and in a front of a passed pawn are most of the time passive pieces. Don’t let the opponent to block passed pawn with the king. That is the reason why it is a good idea to keep major pieces on the board. Trade major pieces only when you see a forced win.

[BeyondCritics]

I get your logic now, but all in all i think i don't agree with it.
But everyone is entitled to its opinion (and let the best player win).

[BeyondCritics]

Say you have this position:
[d] 3r2k1/p1qP1ppp/1p6/3Q4/8/6P1/P4P1P/3R2K1 w - - 0 1
If you would simply take both queens off, the passer would get extremly weak. Is it this, you are fearing?
Still i personaly think, this is more of a special case, than the rule.

[hgm]

According to Nimzowitsch a passed pawn is only dangerous if it is not blocked. So that means a pawn table can not be used to evaluate a passed pawn. Or should it contain information that tells whether passed pawn is blocked or not ?

The Pawn table should indicate the squares where passers can be blocked, so that the evaluation can cheaply award the blocking points depending on what is on that square.

[Karlo Bala]

Say you have this position:
[d] 3r2k1/p1qP1ppp/1p6/3Q4/8/6P1/P4P1P/3R2K1 w - - 0 1
If you would simply take both queens off, the passer would get extremly weak. Is it this, you are fearing?
Still i personaly think, this is more of a special case, than the rule.

Yes. That is a good example. White can activate the rook on fourth or fifth rank, perhaps push h-pawn to squeeze the black on the king side. Combine that with some mate threat...
Is this position the rule or the exception? - I don’t know.

Sometimes it is not easy to make general rules and code them. I would like to hear an opinion from some stronger player than me, perhaps Larry. I have several close friends who are solid GM-s, and when I ask them about some simple rules like material, pawn structure, etc. I always get the same answer: it depends on the position. So, it seems that sometimes it is not so simple.

I think that in computer chess, in general, it is not a good idea to rush things. If one side has a stable advantage (pawn structure, king safety) then there is no need to rush and exchange pieces. The engine should try hard to exploit what it has, and only after all possibilities fails then trade something. People often don't have enough patience but engines can shuffle pieces until the 50-move rule kick in.