15 December 2008

Solve This

Black to move

I had Black and this position against K. Korsmo in the Winter Club Championship two years ago. After the game, I was surprised when Fritz 9 required seven minutes to find my winning idea. It's not often that my understanding exceeds the abilities of my software.

Solve This

Throughout this blog, I use the label "Solve This" when a post has a problem, study, or position from a game, but I have not included the correct line of play within the post. These posts invite solving efforts from readers. Initially, I thought to post problems in this manner, and then a few days later I would follow with "Solve This Solutions." This effort proved more trouble than it was worth, so now I post the answers in the comments after there have been responses.

This post is the 37th labeled "Solve This." Many of these posts have no comments.


  1. I think Rf2+ should win - exchanging rooks and then Kf7, Kg6, etc.

  2. Rolling Pawns, i hope you calculated the push of the pawns on the Q-side when going round with your king to capture the white pawn on e5.

  3. 1...Rf2+ 2.Rxf2 exf2 3.Kxf2 Kf7 looks winning, but my plan differed. Initially the engines prefer your idea, but when given enough time and information, they come over to my way of thinking.

  4. Here's another clue:

    At first Hiarcs 12 finds my idea in a different order, then it shifts to the moves you propose, which it sticks with through 23 ply (11 1/2 moves) analysis. When its analysis depth reaches 24 ply, it fully embraces my idea, and the evaluation improves by two pawns to -4/76.

  5. Pawn push on the queen side gets White a passed pawn eventually, but if Black doesn't advance the king too far, it can stop it, then moving "g" and "h" pawns decides. White goes back, losing that passed pawn and e5 too, it's a win.

    Yeah, chesslab.com gives Rf4, but I still prefer Rf2+, just because it's a clear win.
    James, you advertised such things, remember "Simplify" :).
    I noticed that computer sees very well all the tactics that you missed (so you want like Ivanchuk to kick some pillar :)), but if you do a good move, it happens sometimes that it doesn't see it.

  6. I just found that Black actually has to advance the King if it wants to win, so after pawn breakthrough White gets queen, Black too. It is eventually Q+3P vs. Q, it's a win for Black.
    Interesting endgame.

  7. I did simplify into a king and pawn endgame. 1...Rf2+ 2.Rxf2 exf2 3.Kxf2, but then made a move that my opponent found stunning, and that chess engines prefer after their analysis runs deep enough.

    RP's idea of using the king to usher the kingside pawns forward certainly works, but it seemed to me that the two to one majority could
    fend for itself, while the king had other useful work to perform.

    Hence, 3...a4!! 4.bxa4 Kd7 and on the queenside the king will be able to gobble the a-pawns, then get the opposition for win of the c-pawn.

    Of course, human opponents often find creative responses.

    My opponent opted to maneuver his king behind my pawns by letting the g-pawn escape. In the final position, his a-pawns were still on the board, but my second queen checkmated him immediately after his e-pawn promoted.


  8. Great stuff! Not just a tactic, this is an idea that I will remember for future use. I'm sure your opponent was surprised, since it's a counter intuitive plan on the surface.