Monday, 10 September 2018

7-man Mutual Zugzwangs (KRPP vs KRP)

I have checked this tablebase with SEE, and I have found 119707 mutual zugzwangs where the side with 2 pawns wins only if the other side is to move. Here you can download them in a pgn file:

KRPPvKRP

Here's an interesting one with mutually attacking rooks, both of them being undefended:


mutual zugzwang(!!)

There are also 9030 mutual zugzwangs where the side with 1 pawn wins:

KRPvKRPP

The 70 full point mutual zugzwangs are in both lists, so they are counted twice. Here is a separate list of them:

Full Point Mutual Zugzwangs

Analysing more than a hundred thousand positions isn't feasible but I have developed a method to identify all positions where there are corresponding squares between two rooks. An example:

1. Rh2! Re5 2. Rh1! Rf5 3. Rh4! Rg5 4. Rh3! Rd5 5. Rh2 positional draw

I cannot yet show publicly the two studies I have composed also featuring 4-4 corresponding squares. The best of them is a win study where white must visit every corresponding square before winning! It seems that is unique in this tablebase. Please, don't rediscover it... :)

3 comments:

Marius Mika said...

Excellent and very useful work!
Thanks Arpad.

Árpád Rusz said...

Thanks! KNPP vs KNP will be the next one. I estimate that there are around half a million mutual zugzwangs in that endgame!

Árpád Rusz said...

Well, it seems I have underestimated the number... :D
The first results came out: the software already found over 800000 mutual zugzwangs by limiting the white king to the a1-d1-d4-a4 squares.