K+2N vs. K+P

And Troitzky was famous for "ta da", endgame studies.  How many times is a game you are playing going to result in some esoteric endgame study position? 

It is too easy to demonstrate that you're wrong.

http://www.k4it.de/index.php?topic=egtb&lang=en

You can play around with that all you want. It would also do you some good to read the first page of posts. Natalia posts a link to a wikipedia article on the Troitsky line. It's not just some "ta da" endgame study.

Could you please tell the title of the post, article or blog.  It will save me alot of searching since you seem to know where it is.

Never mind I found the Wikipedia Article.  The article states very clearly that if and when the pawn can be stopped on or before the "Troizsky Line" then checkmate can be forced. But, It text goes on to say:  "...If the defender's pawn is blocked on or before the "Troitzky line", the stronger side can force checkmate, although it may require up to 115 moves with optimal play..."

With the 50 move rule in effect for USCF and FIDE rated tournaments, why would a tournament player be concerned with this endgame.

It is similar to the endgame K+2Bs v. K+N.  In that one which was thought to be a draw for some 300 years, it has been discovered by computers that it is a forced win for the K+2Bs, but it requires some 200 moves to reach checkmate.  Once again the 50 move rule is in effect.  Tournament players don't care except as an interesting fact that a position that was thought to be a draw by Troitzky himself turns out is a forced win for the 2Bs.

I wouldn't be surprised considering that Troizky was wrong about the K+2Bs v K+N, that he might be wrong about the K+2Ns v K+p and one of these days a computer will find that it is a dead draw.

For practical purposes tournament players say, "IDGARA."

I believe K+2B vs. K+N requires at most 70-80 moves with optimal play from both sides, but I'd have to check, and it still exceeds the 50 move rule anyway. For K+2N vs. K+P, it depends on the position, but playing around with the tablebases there seem to be plenty of situations where the 50 moves aren't exceeded with optimal play. Both sides wouldn't play optimally in a tournament setting so mate might be achieved faster or slower than the optimal line of play, or maybe not at all. In a tournament game I would try to play for the win with the two knights, because you can hardly lose and it's a very rare endgame to get the opportunity to play.

I doubt this endgame is worth studying given it's rarity. I don't think I'm even going to bother with it. It's still somewhat interesting though.

@browni3141: Well, check out the Second Trompowsky Line to see which positions are less than 50 moves till mate. The endgame has little practical use, but understanding the ideas will help your chess.

Hm, I sense a contradiction in there somewhere...

Big Mystery. In the book 'The Greatest Ever Chess Endgames', with regard to the diagram that opens this post, the author claims that if the black King heads towards the a1 corner (opposite the corner containing the pawn) then he will be mated.  However he gives limited variations, and leaves off before showing how the black King actually can be cornered.  I cannot find a way to force this (using Fritz 12).  In the game analysed (Znosko Borovsky - Seitz (1931)) the defending King is mated in the same corner as his pawn.  Go top the opposite corner!  Where's the mate?  Can anyone point it out?

Fritz is a weak, old engine. Use Stockfish (free here) and add tablebases for perfect endgame play...

Any position is a win for the stronger side.

The stronger side in this endgame can be White or Black or neither, but White has better chances than Black.

Mostly it's drawn.

Well here us szygy tablebase

https://syzygy-tables.info/?fen=4k3/p7/8/8/8/8/1NN5/4K3_w_-_-_0_1

This one was constructed with 50 moves draw rule( statistics are not related to current 75 moves draw rule). The stats says,

1. KNN  win in 14.6 % of games under 50 moves rules

2. KNN win additional 7.2% of games if there is no draw rules

3. 70.3 % are draw

4. Although there is 0% KP win beyond 50 moves draw rules there is 30000+ games in this condition (0.00 means rounded to 2 decimals .)

5. There is 7.9% KP win under 50 moves draw rule

The Syzygy tablebase alone won't tell you that, you need extra software to trawl the tablebase. Do you know if there is any freely available? I use Wilhelm/Nalimov which is (almost) correct for games where the 50 move rule doesn't apply (the majority these days), but remove positions which immediately resolve to a simpler ending (unprotected knights en prise etc.).

SYZGY is a 100% completely calculated mathematical data that forced the computers to calculate all possible brute forced moves.

It is 100% completely pure mathematics.

It tells you everything.

See my post above.

There is 500 million plus positions with KNN vs KP. Out of all those 500 million positions, the data base can tell you how black or white can win in how many moves.

Thanks for that - I didn't know the site gave those stats. What do you click on to get the info?

Notice there is no point at which the 50 move rule could be invoked. Syzygy says there is a defence by Black that wriggles out of the win under the 50 move rule, but the chances of meeting any player who can play accurately taking the 50 move rule into account are nil. In any case the 50 move rule doesn't apply in the majority of games these days.

This post http://galen.metapath.org/egtb50/ gives a position where mate can be forced within the 50 move rule but needs 112 moves with perfect play by both sides under that rule.

Just put any possible 7 men position on the site in my above link, the site tells all those statistics in the bottom of the page.

@drmrboss

Thanks again. Red face job - I just didn't scroll down.

Do you have the Troitzky KBBKN position in question?