GMTonyKosten wrote on 02/12/06 at 07:04:54:


So a rook and pawn can be stronger than two pieces AND a rook isn't much stronger than a piece and pawn.  At the end of the day, I'm awfully tempted to try to keep all my pieces on the board at all costs...   

This is really a complicated issue, as there is another chapter in Mihail Marin's Learn from the Legends devoted to Tal's 'sacrifices' of two pieces for a rook. So if rook and pawn often beat two pieces in an endgame, how can a rook not be far better than one piece?
For instance, I saw Sokolov happily go for an exchange of two pieces for a rook and two pawns against Tkachiev the other day, he was happy to do this as his opponent was obliged to swap queens at the same time.

This devaluing rooks like so many other things is just a fad! I wish more folks would sacrifice their rooks! I'd be able to notch up a few more points in tourney play

For pawns you would have to factor in the chance of promotion and the value of the queen. So better first start with the queen. Then again I am still working on my mathematical proof of the inferiority of 1 d4 relative to 1 e4, so it may take a while

Let's settle this once and for all with math
Position
White: Kh1, Rg1
Black: Kh8, Bh7

Now whether you remove the rook or keep it on, the result is still a draw. With the bishop off the result changes to a loss.
So
R vs B=draw
- vs B=draw
R vs -=1-0
So 2 R= 1.5 and 2 B=1-->1.33R=2B-->1R=1.5B. Now assuming a B is worth 3 points, then a rook is 4.5 points

I played an interesting game abt 1.5 yrs ago with one of my mates. It was a Najdorf & I made a thematic Rxc3 sac - Rook for kt + King pawn + active minor piece play in the ctr. The game progressed towards the ending where I had a Kt + 3-4 pawns  whilst he had a rook & pawn. (sorry didnt record the game)

I eventually won the ending, but after the game I studied a particular position as I somehow felt that he had some 'swindling' possibilities. What I vaguely remember now is that if he saced his rook for 1 of my pawns, amazingly the whole game would be drawn!! It was fortunate in a way for me that he wasnt the type of player to go for sacs of any kind!

Its kind of difficult to really judge if a rook sac is going to work or not esp if its not for mate or immediate material gain. Piece activity, open lines,initiative is also not necessarily a permanent or lasting advantage but a plus pt for the short term at least. Pity there are no real rule of thumb to actually gauge it accurately even in GM play. Best part is that most of the time such sacs arent the product of very deep calculations. Quite a fair bit of inspiration, intuition, keen judgement & of course the opponent somehow going wrong especially in complications.

Well, simply, value varies with fase of the game, and especially rooks normally have to wait until the endgame to demonstrate their worth. So if you are sure there will be no endgame it is an easy decision...