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Unusual endings
Posted: Mon Jul 05, 2021 7:43 am
by Andy Stoker
I am playing a game of "Daily Chess" on chess.com (akin to correspondence chess) and reached an ending I had never seen before - I had bare K, Q, R, R (no pawns) - opponent had K, Q, N, P, P, P - the 3 pawns being on f7, g6, h7. The game has now progressed to a R vs 3P ending covered by Reuben Fine, which I hope to win shortly - I should say no more as the game is in progress.
... but my question is, how unusual is such an ending? I had never seen anything like it. Is it possible to search databases for this and other unusual material imbalances?
Re: Unusual endings
Posted: Mon Jul 05, 2021 8:03 am
by Roger de Coverly
Andy Stoker wrote: ↑Mon Jul 05, 2021 7:43 am
Is it possible to search databases for this and other unusual material imbalances?
Certainly, but it's likely to be part of their more advanced features and sometimes difficult to use as a consequence. You are probably banned from using them during play, but R v 3 pawns is within the scope of six man tablebases.
Re: Unusual endings
Posted: Mon Jul 05, 2021 8:36 am
by Kevin Thurlow
"You are probably banned from using them during play, but R v 3 pawns is within the scope of six man tablebases."
Ironically, if you are playing ICCF events you can make claims based on 7-man tablebases, but ICCF don't ban any sort of computer.
The original ending sounds fascinating!
Re: Unusual endings
Posted: Mon Jul 05, 2021 9:34 am
by Ian Thompson
Andy Stoker wrote: ↑Mon Jul 05, 2021 7:43 am
How unusual is such an ending?
One in a few million games if my database is anything to go by (ignoring games where the material balance occurred for one move during a series of captures).
Andy Stoker wrote: ↑Mon Jul 05, 2021 7:43 am
Is it possible to search databases for this and other unusual material imbalances?
Yes. Easy.
Re: Unusual endings
Posted: Mon Jul 05, 2021 10:10 am
by Roger de Coverly
Andy Stoker wrote: ↑Mon Jul 05, 2021 7:43 am
I am playing a game of "Daily Chess" on chess.com (akin to correspondence chess) and reached an ending I had never seen before - I had bare K, Q, R, R (no pawns) - opponent had K, Q, N, P, P, P - the 3 pawns being on f7, g6, h7. The game has now progressed to a R vs 3P ending
That's actually the logical plan. First get the queens off, then sacrifice the exchange to reach R v 3 pawns. If the opponent declines to trade queens or allow an exchange sacrifice, progress might be made with mating threats or threats to win pawns. R v 3 isn't always won though if the pawns are connected and get well advanced supported by the King.
Re: Unusual endings
Posted: Mon Jul 05, 2021 10:47 am
by Andy Stoker
Thank you Roger - that indeed was my plan - once I'd stopped the threats of perpetual and managed not to leave my rooks loose or forkable ... in fact he allowed the exchange sac first and then exchanged queens the first time I offered them - and headed straight for the wrong side of one of Fine's examples (297a)
The game will be full of inaccuracies but I can share once we've finished... how do I put it in the figurine notation with a diagram?
Re: Unusual endings
Posted: Mon Jul 05, 2021 11:07 am
by Roger de Coverly
Andy Stoker wrote: ↑Mon Jul 05, 2021 10:47 am
how do I put it in the figurine notation with a diagram?
There's a recent thread under "News and Support"
viewtopic.php?f=8&t=11788
Re: Unusual endings
Posted: Mon Jul 05, 2021 11:31 am
by Andy Stoker
Excellent - thank you again