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Normal Topic Material on a Specific Rook Ending (Read 3979 times)
kylemeister
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Re: Material on a Specific Rook Ending
Reply #4 - 08/27/14 at 20:24:40
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Such an ending reminds me of Karpov-Hort, Waddinxveen 1979 (analyzed in a book by Timman), though Black wasn't a pawn down in that case.
  
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TonyRo
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Re: Material on a Specific Rook Ending
Reply #3 - 08/27/14 at 20:11:03
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Yeah - I'm guessing that the verdict of this depends a lot on the relative locations of the kings and how far advanced each sides pawns are. For instance, just switching it up a bit:

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I can likely start with 1.Ra5, fixing the a6-pawn in place, or just 1.Kf2 - but how does Black stop White from trading h-pawn for g6-pawn, reaching the tablebase win discussed in my first post? In this case White's pawns are more advanced (and Black's a-pawn is not), his king activates more quickly, and the g-pawn being on g6 makes it easier to trade it off.
  
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Smyslov_Fan
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Re: Material on a Specific Rook Ending
Reply #2 - 08/27/14 at 19:42:24
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I haven't found too many examples with similar imbalances to this one, but I'm guessing that Black should be able to draw this. The a-pawn isn't far advanced, but it still requires vigilance from White. That should be enough to ensure the draw, as long as Black can keep the g-pawn until the play simplifies.
  
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kylemeister
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Re: Material on a Specific Rook Ending
Reply #1 - 08/27/14 at 19:05:39
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I notice that Fine used Euwe-Alekhine (game 1, 1937) as being typical.  In that one Black had h- and c-pawns.
  
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TonyRo
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Material on a Specific Rook Ending
08/26/14 at 23:28:18
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I've been studying some rook endings lately, and was wondering about a specific pawn configuration - is there any theoretical consensus or material I could check out on single rook endings that look like this:

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Basically 3 vs. 1 for the attacker on one side, and 1 vs. 0 for the defender on the opposite flank?

If you remove a pawn from White's side and Black's g7-pawn, while keeping White's passers connected, it's a win whether or not he gets the g and h-pawns or the f and g-pawns, e.g. this is a win, whether Black's rook is along the third rank or on a7/a8:

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But this is apparently a draw according to the Lomonosov TBs:

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The former tablebase positions being a win is interesting in and of itself - the position without Black's a-pawn is an easy win for White if he knows how to avoid the stalemate tricks, but it's funny to me that Black's a-pawn means nothing. But yet, if you move it one square further, it's a draw, e.g.:

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But wait, there's more! It's fairly well known that the g and h-pawns are the worst case scenario - make them f and g-pawns, and even with the pawn on a5, this position is a win for White:

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I'll spare you guys another diagram, but move the a-pawn forward one more square to a4, and it's a draw again, even with the f and g-pawns.



  
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