weird exchange

Originally posted by el gil
is it a good idea to trade a bishop and a knight to take a rook+1 pawn??

Generally, no.

Assuming you trade down into the endgame, usually the combined power of the bishop and knight overpower the lone rook.

Originally posted by el gil
is it a good idea to trade a bishop and a knight to take a rook+1 pawn??

The answer to all this kind of questions (what is most worth? a xxx or a yyy?) is of course - It depends of the situation. There is no general advice here that covers all situations and positions.

A pawn that is about to promote is worth as much as a queen and it can save the game to sacrifice a rook to prevent it. just an example of many.

The value of any position si not worth only the sum of the pieces on board. You have to acount of king safety, open lines, interplay between pieces, center occupation and a lot of othere properties of the position. Fritz and like calculate all these things together and decides if it helps the situation to exchange (in this case a bishop and a knight to a rook+1 pawn). Fritz know how to calculate all properties very quickly, we mere humans has to rely to intuition and experience, sometimes on courage and psychology.

So the short answer to these kind of questions is - It depends...

Originally posted by el gil
is it a good idea to trade a bishop and a knight to take a rook+1 pawn??

FabianFnas is correct, in that the answer to your question always depends on the specific board position. But if you need a general answer to your question, then wittywonka's answer is also correct. Generally, it's not a good idea.

Larry Kaufman's 1999 Chess Life article, The Evaluation of Material Imbalances, has a paragraph related to your question. (The section titled Two Minor Pieces vs. Rook And Pawn(s).) Larry also gives an example of a trade in the opening where it's not a good trade for the side giving up the bishop and knight. You can read Larry's article on the link below.

http://mywebpages.comcast.net/danheisman/Articles/evaluation_of_material_imbalance.htm

Originally posted by el gil
is it a good idea to trade a bishop and a knight to take a rook+1 pawn??

Probably not, since it takes two of your best developed pieces out of action and generally speeds the opponent's development. But in chess, there are no absolutes -- it all depends on the position on the board.