Reflexmate

From Wikipedia, the free encyclopedia

This article uses algebraic notation to describe chess moves.

A reflexmate is a chess problem in which white, moving first, must force black to deliver checkmate within a specified number of moves against his will. Moreover, there is added condition that if either player can give checkmate, they must. If this condition applies only to Black, it is a semi-reflexmate. (Without this condition the problem is just ordinary selfmate.)

Štefan Sovík, second Place IV WCCT 1990
Image:chess zhor 26.png
Image:chess zver 26.png a8 b8 c8 rl d8 rd e8 kd f8 g8 h8 Image:chess zver 26.png
a7 b7 c7 pd d7 e7 nd f7 g7 h7
a6 b6 c6 d6 e6 f6 pl g6 bd h6 bd
a5 pl b5 qd c5 d5 e5 pl f5 ql g5 h5
a4 bl b4 pd c4 rl d4 bl e4 nl f4 g4 pl h4 pl
a3 b3 rd c3 pd d3 kl e3 pd f3 g3 h3
a2 b2 c2 d2 e2 pl f2 g2 h2
a1 nd b1 nl c1 d1 e1 f1 g1 h1
Image:chess zhor 26.png
Reflexmate in two moves

The problem to the right is a fairly recent example successful in World Chess Composing Tournament despite single phase present. It is by Štefan Sovík and is a reflexmate in two moves.

The key is 1.Qh5! and white threats 2.Nbxc3, after which black is compelled by additional condition to mate by Rxc3#, with triple pin of Rc4, Bd4 and Ne4.

There are three thematical variations with upins of three pieces, but every time Black has to mate by switchback after selfpin of unpinned piece on c3:

  • 1...Qxa4 2.Rxc3 Qb5# (white move: rook unpinned by queen move selfpins)
  • 1...Rxc8 2.Bxc3 Rd8# (white move: bishop unpinned by rook move selfpins)
  • 1...Bxh5 2.Nxc3 Bg6# (white move: knight unpinned by bishop move selfpins)

Further three variations result in upins of white pieces, but the mates are not by switchback:

  • 1...Qd7 2.Rc6 Qxd4# (white move: unpinned rook unguards d4 and unpins queen)
  • 1...Nd5 2.Bxe3 Nf4# (white move: unpinned bishop opens d-file and blocks e3)
  • 1...Kd7 2.Bxc3 Kxc8# (white move: unpinned bishop opens d-file and selfpins on c3)

In next three variations the black pieces are unpinned and mate:

  • 1...Qc6 2.Bxb3 Qxe4# (white move: bishop unpins queen)
  • 1...Nf5 2.Rxc7 Rxd4# (white move: rook unpins rook)
  • 1...Bf7 2.Qf5 Bxc4# (white move: queen unpins bishop)

The last variation is just technical:

  • 1...Rxb1 2.Bd1 Rxd1#

The example is putting emphasis on unpinning and pinning (see motivation) and illustrates one of the artistic advantages of reflexmate over selfmate, namely the presence of more varied mates (on average).

Languages