The wonderful end-games of Team-Mate Chess
Posted: Tue Oct 14, 2014 10:06 am
I created a novel Chess variant, which distinguishes itself by the peculiarity that no single piece occurring in it has mating potential. So Checkmates will also have to be performed by pairs of pieces. Hence the name 'Team-Mate Chess'.
For people that like KBNK this would be the ultimate Chess variant! To have maximum variety in the possible 3+1 end-games, all eight back-rank pieces are different. This gives 7*6/2 = 21 possible 3+1 end-games. Because there is another piece that can only be obtained through promotion (and it is the strongest piece you can promote to!), there will be another 7 heterogeneous pairs that can occur after promotion. Of those, 28 piece combinations, only one is not a general win. So there are 27 new checkmates. Two of the pieces are color bound, so that when they participate mate might only be forcible in two of the four corners.
The pieces are:
Queen replacement(s):
* Ancaa, a 'double-barrel' Bishop which first makes an orthogonal step before bending in the (outward) diagonal direction. The Ancaa is a color-alternator. Worth about 8. It is not eligible as promotion choice.
* Adjutant, a Queen that skips all odd squares of her Rook moves (irrespective of whether these squares are occupied or not). Color bound, and worth about 7. It can only be obtained through promotion.
Rook replacements:
* Cobra, jumping as Knight, but also able to continue from there (if the square was empty) one outward orthogonal step (for a (1,3) move). Worth about 5.5.
* Unicorn, jumping as Knight or making a single orthogonal step. It is also a color alternator. Worth about 5.
Minor replacements (worth about 3):
* Elephant, moving one step diagonally, or jumping two. Color bound.
* Mammoth, jumping two or three steps diagonally. Color bound. (Perhaps worth only 2.5)
* the orthodox Knight, a color alternator.
* Phoenix, stepping one orthogonally, or jumping two diagonally.
King and Pawn are as in orthodox Chess, except that the King can castle with any of the Rook replacements.
The only pair without mating potential is Knight + Mammothl. I did not include an orthodox Bishop, because the Elephant is very similar as far as forcing the mate goes, and slightly more challenging because it lacks the long-range moves. The two color-bound pieces start on opposite color, and in this case they can force mate. There is a large variety of strategies for the final checkmates; not only the standard corner (a1) and edge (b1) positions with the King on b3, but also on c1, or with the strong King on c3.
The new version of Fairy-Max (which will be included with WinBoard 4.8.0) will play this variant. Surprisingly enough it does not seem any more drawish than orthodox Chess, despite the fact that KPK is always draw. At least in Fairy-Max self-play, about 26% of the games ends in draws.
For people that like KBNK this would be the ultimate Chess variant! To have maximum variety in the possible 3+1 end-games, all eight back-rank pieces are different. This gives 7*6/2 = 21 possible 3+1 end-games. Because there is another piece that can only be obtained through promotion (and it is the strongest piece you can promote to!), there will be another 7 heterogeneous pairs that can occur after promotion. Of those, 28 piece combinations, only one is not a general win. So there are 27 new checkmates. Two of the pieces are color bound, so that when they participate mate might only be forcible in two of the four corners.
The pieces are:
Queen replacement(s):
* Ancaa, a 'double-barrel' Bishop which first makes an orthogonal step before bending in the (outward) diagonal direction. The Ancaa is a color-alternator. Worth about 8. It is not eligible as promotion choice.
* Adjutant, a Queen that skips all odd squares of her Rook moves (irrespective of whether these squares are occupied or not). Color bound, and worth about 7. It can only be obtained through promotion.
Rook replacements:
* Cobra, jumping as Knight, but also able to continue from there (if the square was empty) one outward orthogonal step (for a (1,3) move). Worth about 5.5.
* Unicorn, jumping as Knight or making a single orthogonal step. It is also a color alternator. Worth about 5.
Minor replacements (worth about 3):
* Elephant, moving one step diagonally, or jumping two. Color bound.
* Mammoth, jumping two or three steps diagonally. Color bound. (Perhaps worth only 2.5)
* the orthodox Knight, a color alternator.
* Phoenix, stepping one orthogonally, or jumping two diagonally.
King and Pawn are as in orthodox Chess, except that the King can castle with any of the Rook replacements.
The only pair without mating potential is Knight + Mammothl. I did not include an orthodox Bishop, because the Elephant is very similar as far as forcing the mate goes, and slightly more challenging because it lacks the long-range moves. The two color-bound pieces start on opposite color, and in this case they can force mate. There is a large variety of strategies for the final checkmates; not only the standard corner (a1) and edge (b1) positions with the King on b3, but also on c1, or with the strong King on c3.
The new version of Fairy-Max (which will be included with WinBoard 4.8.0) will play this variant. Surprisingly enough it does not seem any more drawish than orthodox Chess, despite the fact that KPK is always draw. At least in Fairy-Max self-play, about 26% of the games ends in draws.