Kamikaze Chess

Fairy chess problems are akin to fantasy fiction and other genres of non-realistic stories in which “impossible” things occur. Such problems may employ unorthodox pieces (for example, the previously introduced grasshoppers and nightriders), which are analogous to imaginary beings with special powers. Another major type of unorthodox element – one that hasn’t been examined on this site before – is the fairy condition, which refers to an unconventional rule of play. Applying such a condition to a problem is rather like changing the laws of physics in a science fiction tale. In both cases we are asking, “What if?”, meaning we want to explore the interesting effects and consequences of modifying certain rules.

Myriad fairy conditions have been invented, varying in complexity and the degree to which they deviate from the regular game. One of the simplest is Kamikaze Chess. In this variant, when a capture occurs, both the capturing and captured pieces are removed from the board. Only the kings are exempt from this rule and they capture normally. What kinds of effects are possible with this condition? One basic way to exploit the rule is to utilise captures as a line-opening device – that is, a player can instantaneously open a line blocked by an enemy unit by capturing it. This tactic is used repeatedly in the two Kamikaze helpmates below.

The first position has a pair of R + B batteries aimed at the black king, but two orthogonal flights must be covered and further, the black knight is poised to counter either rook check and it cannot move without yielding a third flight. The only way to deal with these hurdles is for White to deliver a double-check(mate) with the two rooks, achievable if the battery-firing bishop were to capture a black piece standing on the other rook line. Two additional line-opening captures are needed to set up such a double-check, which is obviously impossible in orthodox chess: 1.Q*e7 B*b3+ 2.Ra3 B*a3 (an ‘*’ designates a fairy capture). The twin (b) produces similar play: 1.R*f7 B*g7+ 2.Qg8 B*g8. The two white bishops reverse their roles and so do the black rook and queen. There’s also a reciprocal relationship between the a2-bishop and f3-rook in that each piece sacrifices itself to open a line for the other, and likewise for the f8-bishop and g5-queen.

The next problem comprises four phases of play that revolve around the two arranged pins. The solutions all entail organising a mate along one of the initial pin-lines, with the other pin required for the mate. First, the h6-rook can mate if the queen is allowed to open the h-file with a sacrificial capture: 1.Sd7 Qc5 2.S*e5 Q*h5. Second, the queen is given access to the potential mating square c8 by 1.S*c6, but now if White clears the diagonal with 1…B*g4?, Black will have no waiting move available to permit the queen mate. Instead, the unpin 1…Bg8 enables the black rook to remove itself with 2.R*g8, so that it cannot spoil 2…Qc8 with a switchback. The two solutions in part (b) closely match those in (a), and for each respective pair the strategic effects undergo an orthogonal-diagonal transformation. 1.Sc3 Qd1 2.S*e2 Q*g4 and 1.S*d2 Rg6 (not R*h5?) 2.B*g6 Qh6. The problem thus illustrates the Helpmates of the Future scheme in which two pairs of corresponding solutions are brought about.