7-piece tablebase win in 517 moves

[GothicChessInventor]

I am putting together a list of the longest wins found in the chess tablebases. While most of you may have seen some long 6-piece tablebase wins, many of the 7-piece wins have not been published yet.

http://www.gothicchess.com/javascript_8 ... dings.html

The page above shows the position, the line of optimal play with best defense, and a link to a javascript utility to let you play through the ending.

Other sites I have seen usually just give the position as a FEN string with no position, or the position with no moves, or just the position and the distance to win. The link above is much more complete, but I need more "longest wins" to add to the list!

If you know of any wins, and have the positions saved as PGN files, let me know. I can convert the PGN to a web viewable file rather easily.

Thanks!

[M ANSARI]

Amazing !!! I think the 50 move rule should certainly be modified now. This shows how rich chess really is and how clueless we all are about its inner secrets.

[Graham Banks]

Amazing !!! I think the 50 move rule should certainly be modified now. This shows how rich chess really is and how clueless we all are about its inner secrets.

I think that the 50 move rule is needed for sanity's sake!

[hgm]

I am putting together a list of the longest wins found in the chess tablebases.

I once did an EGTB for KbmKh (= Bishop + Commoner against Nightrider). The maximum DTC was 308 moves, which is quite exceptional for a 5-men end-game (note that DTM will be significantly longer, as KbmK is not so easily won either). Even the average DTC was 265.5 moves! Nightrides are quite difficult to catch!

Unfortunately I lost the maximin position when the HD of my laptop crashed. I could easily recalculate it, though, if you are interested; that would only take a few minutes.

[M ANSARI]

I am putting together a list of the longest wins found in the chess tablebases.

I once did an EGTB for KbmKh (= Bishop + Commoner against Nightrider). The maximum DTC was 308 moves, which is quite exceptional for a 5-men end-game (note that DTM will be significantly longer, as KbmK is not so easily won either). Even the average DTC was 265.5 moves! Nightrides are quite difficult to catch!

Unfortunately I lost the maximin position when the HD of my laptop crashed. I could easily recalculate it, though, if you are interested; that would only take a few minutes.

I really like the way you address endgame play by computers. I think that with the increasing power of hardware ... you could use your system to write appropriate EGTB's on the fly. You would first need a table of win, lose or draw data ... then if there is a win or a way to avoid a loss the computer would go into one of your modules and find the correct sequence of moves. Why don't you do an open source endgame module ... I am sure every engine could make good use of it.

[rlsuth]

Amazing !!! I think the 50 move rule should certainly be modified now. This shows how rich chess really is and how clueless we all are about its inner secrets.

You're kidding, right?

Apart from the incredible boredom that would possibly create, do you think anybody could possibly memorize all combinations to produce a 517 move mate?

[GothicChessInventor]

Are you guys so young that you were unaware that the 50 move rule was changed to 75 moves, later 100 moves, and finally, after several protests, was brought back down to 50?

It all started after Ken Thompson showed some wins being much longer 50 in certain endgames. FIDE's thinking was: If you're in a won position, you should be allowed to try and win it. The rule was extended when even larger tablebase wins were produced.

Finally, when it became more than apparent that this was the domain of computers-only, they changed it back.

[GothicChessInventor]

I once did an EGTB for KbmKh (= Bishop + Commoner against Nightrider). The maximum DTC was 308 moves, which is quite exceptional for a 5-men end-game (note that DTM will be significantly longer, as KbmK is not so easily won either). Even the average DTC was 265.5 moves! Nightrides are quite difficult to catch!

Unfortunately I lost the maximin position when the HD of my laptop crashed. I could easily recalculate it, though, if you are interested; that would only take a few minutes.

Endgames are fun to compute, aren't they? I'm not even sure how a nightrider moves to be honest. By "commoner" do you mean "pawn", or is this another piece?

My favorite ending is Archbishop vs. Bishop + Knight (a piece that does on 1 square what the opposing side does on 2 squares!)



Mate in 202!

http://www.gothicchess.com/endings/kakbn/game.htm

[Graham Banks]

Are you guys so young that you were unaware that the 50 move rule was changed to 75 moves, later 100 moves, and finally, after several protests, was brought back down to 50?

It all started after Ken Thompson showed some wins being much longer 50 in certain endgames. FIDE's thinking was: If you're in a won position, you should be allowed to try and win it. The rule was extended when even larger tablebase wins were produced.

Finally, when it became more than apparent that this was the domain of computers-only, they changed it back.

And rightly so. Just my humble opinion.

[Uri Blass]

I once did an EGTB for KbmKh (= Bishop + Commoner against Nightrider). The maximum DTC was 308 moves, which is quite exceptional for a 5-men end-game (note that DTM will be significantly longer, as KbmK is not so easily won either). Even the average DTC was 265.5 moves! Nightrides are quite difficult to catch!

Unfortunately I lost the maximin position when the HD of my laptop crashed. I could easily recalculate it, though, if you are interested; that would only take a few minutes.

Endgames are fun to compute, aren't they? I'm not even sure how a nightrider moves to be honest. By "commoner" do you mean "pawn", or is this another piece?

Commoner moves as a king but it is possible to capture it without finishing the game.

I am also not sure about the nightrider rules but I think that it was explained in the programming subforum.

Uri