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  1. 07 Jun '07 20:07 / 1 edit
    Common sense tells me that white ought to be able to win with the extra rook. So do various online sources, which suggest that in most (if not all) positions, this is a win for white. But I've just spent a frustrating game failing to achieve checkmate. Eventually I blundered and lost the extra rook, but I'm confused about how checkmate could have been achieved when my opponent was unwilling to exchange rooks. I haven't been able to find anything about how to achieve mate with this combination on the board. The problems are:

    1) To achieve mate, the black king needs to be driven to the edge of the board. However, from most positions, the king is close enough to the white rooks that it can move diagonally to intercept them as they advance up the board and thus prevent checkmate. If the rooks defend themselves by moving onto the same rank or file, the king is then able to slip between them when one moves; thus the king cannot be confined to the edge of the board.

    2) The above problem would not apply if it were not for the extra black rook, since in a 2 rooks plus king scenario, the rooks can dart across the board in a couple of moves and continue to force the king towards the edge. However, when black still has a rook, the moves required to get white's rooks over to the other side of the board are enough for the black rook to move up and shield the king. The only way for white to force an exchange is to move both rooks onto the same rank or file, so that the rook can be attacked by a piece which is in turn defended. But that takes two moves to achieve, so as soon as white makes the first, the black rook can move out of the way again; white then has to move back onto adjacent ranks / files to have a hope of checkmating; if he does so, that gives black a chance to move the rook again and thus the process repeats itself. Usually black can spend some intervening moves chasing white's king around the board, wasting moves and leading towards a draw.

    3) Lastly, if white tries to get his king up the board to restrict black's own king's movements, this gets in the way of the squares at least one of his rooks is attacking; and then the black king can sneak away from the edge of the board on the far side of the white king.

    I'm not a great player so I am probably overlooking something obvious, but it looks to me that unless black makes a mistake and puts his rook into a position where a white rook can pin it against the king, the result is going to end up being a draw. But sources seem to agree that this game can be won by white. The position at the start of the endgame is shown here. I'd be very grateful if someone could tell me how I should have won this game!
  2. 07 Jun '07 20:16
    That was what I was trying to do... but is it always possible to force a swap? The position at the beginning of the endgame was White King on E1, White Rooks on A4 and B4, Bloack King on G6, and Black Rook on C2.
  3. 07 Jun '07 21:31
    Originally posted by Teinosuke
    That was what I was trying to do... but is it always possible to force a swap? The position at the beginning of the endgame was White King on E1, White Rooks on A4 and B4, Bloack King on G6, and Black Rook on C2.
    I tried this against Rybka, with Rybka at approx 30 secs per move but no tablebases installed (I guess tablebases would be harder). From your start position:



    1. Rb5 Rc6 2. Kf2 Kf6 3. Kf3 Ke6 4. Ke4 Kd6 5. Kd4 Ke6 6. Ke4 Kd6 7. Rd5+ Kc7 8. Ke5 Rc3 9. Ra6 Rh3 10. Rdd6 Rh5+ 11. Kf4 Rh1 12. Rf6 Rf1+ 13. Ke5 Re1+ 14.Kf5 Rf1+ 15. Kg6 Rg1+ 16. Kf7 Kb8 17. Rae6 Kc8 18. Re7 Kd8 19. Ra7 Rh1 20. Kg7 Rg1+ 21. Kf8 Kc8 22. Rff7 Rb1 23. Ra8+ Rb8 24. Rxb8+ Kxb8 * and White wins

    I think you have to use your rooks in a "scissor" manner to drive the king back. Black's rook has to become passive to prevent this, and then you need to improve the position of your pieces... bringing in your own king and also using your rooks in both directions to further minimise the mobility of the Black king. Also, sometimes need to use your own rook to shield you king from checks.
  4. 07 Jun '07 22:23
    Your game is still in progress. Finish the game first, then we'll talk.
  5. 07 Jun '07 22:34
    Just trade rook for rook and mate him w/ king + rook vs king.

    Can't give you game specific advice if its still in progress, but you can reference past chess games etc...

    here is a funny game from chessgames.com between deep junior and deep fritz where deep junior tries unsuccessfully for several moves to GIVE AWAY a rook just so it can have rook + king + pawn vs rook + king because that piece setup allowed it to access its endgame books to figure a mate, even though it put it in a terrible position... it finishes with white having rook + king vs king and mating... even if its no help, its a cool game.

    http://www.chessgames.com/perl/chessgame?gid=1220622
  6. 07 Jun '07 22:46
    Sorry, I didn't think this was a game in progress

    I'd delete/edit my post, but I can't see an option to do so.
  7. 07 Jun '07 23:12 / 1 edit
    Not sure if it matters, the game is now king + rook vs. king + rook.
  8. 07 Jun '07 23:19
    Originally posted by Jake Ellison
    Not sure if it matters, the game is now king + rook vs. king + rook.
    Nope, it doesn't make any difference. A moderator recently clarified this issue by saying that we shouldn't comment on a game in progress, even if it's only commenting on a prior move that appears to have no bearing on the later parts of the game. A poster might think he's making an innocent comment that can't possibly have any bearing on the rest of the game, but sometimes it CAN make a difference. So to be safe, the best approach is simply that no comments about the game of any kind should be made until the game is over.
  9. 08 Jun '07 15:50
    A moderator recently clarified this issue by saying that we shouldn't comment on a game in progress, even if it's only commenting on a prior move that appears to have no bearing on the later parts of the game.
    Sorry - I didn't realise that was the rule. I'd waited till I lost the rook before posting, when the matter seemed academic. Rule noted for future posts.

    The game has now drawn, so comment can proceed.

    Everyone seems to advise trading off one of the rooks, but my opponent obviously knew I'd beat him if we got down to rook and king v. king, so just kept moving his king and rook around to prevent me exchanging. As long as he was canny in where he put his pieces, it seemed like he could basically avoid the exchange indefinitely. For the reasons I listed in my first post, the extra rook gives black a remarkable degree of flexibility.
  10. Forum Moderator
    08 Jun '07 17:08
    Originally posted by ShaKKaXulu
    Just trade rook for rook and mate him w/ king + rook vs king.

    Can't give you game specific advice if its still in progress, but you can reference past chess games etc...

    here is a funny game from chessgames.com between deep junior and deep fritz where deep junior tries unsuccessfully for several moves to GIVE AWAY a rook just so it can have rook + k ...[text shortened]... . even if its no help, its a cool game.

    http://www.chessgames.com/perl/chessgame?gid=1220622
    You just did give game specific advice, you've told this user to trade rooks.