The Striptease theme

The twinning device, or altering a diagram to produce more solving positions, usually serves a constructional purpose only, to increase a problem’s content. Certain types of twinning, however, can become the main focus of a problem, especially when the adjustments made are harmonious. The Striptease theme (introduced in the previous Walkabout) represents one of these special twin forms, in which all new positions are created by progressive removals of units from the original diagram. Composing such multiple positions with varied solutions is a technical feat in itself, hence we don’t necessarily expect examples to display highly sophisticated strategies as well. Nevertheless, the best renditions tend to include additional thematic features that connect the various parts.

Our first illustration is an uncomplicated miniature, but the solutions avoiding stalemate are not trivial. In the first four parts, White employs different key-pieces, each of which gets removed to create the next starting position. Part (a) is solved by 1.Rf2! Kg1 2.Rf1, (b) by 1.Se3! Kg1 2.Qg2, (c) by 1.Be5! Kg1 2.Qxh2, and (d) by 1.Qe2! Kg1 2.Qf1. Four changed mates for 1…Kg1 are neatly brought about. Part (e) gets rid of the black pawn to leave the barest (pun intended!) material of three pieces, and it’s solved by 1.Kf2! Kh2 2.Qh6.

The white pawn on the 7th rank coupled with the four parts point to a well-known promotion theme. The solutions are: (a) 1.c8=S+! Kb8 2.c7, (b) 1.c8=B! Kb8 2.Sc6, (c) 1.c8=R! Ka6 2.Ra8, and (d) 1.c8=Q! Kb6 2.Qb7. Striptease twinning is ingeniously combined with Allumwandlung, where the four promotion types occur in ascending order. Two-move miniatures that qualify for the FIDE Albums are scarce, and this is the only one from the 1965-67 collection.

In this complete block position, all legal black moves are provided with set mates: 1…g4 2.Rf5 and 1…Rxh7 2.Rxh7. White wants to preserve the zugzwang, and despite the large white force, only one waiting move is available. Not 1.h8=Q? Rxh8!, 1.Kh3? g4+!, or 1.f4? gxf4+!, but 1.f3!, retaining the set variations. The absent f2-pawn in (b) frees up a square for 1.Sf2! Likewise in (c), 1.Rh1! is possible without the h1-knight, though here the key entails a threat, 2.Bg1. The next two parts return to waiting play, and continue the pattern of the key-piece accessing the newly vacant square: (d) 1.Bg1! and (e) 1.Sh2! In (f), White seems to have run out of pieces to make a neutral move. However, the removal of five units has cleared a U-shaped path for the f7-rook to play 1.Rf1! and threaten 2.Rh1, which is a new way to counter 1…Rxh7. A humorous problem with a twist in the tail.

Helpmate problems are perhaps more conducive in delivering the Striptease theme, and intensive presentations with more than ten parts are known. Here’s a more moderate but first-class example. Part (a) is solved by 1.Kg4 Rg7+ 2.Kh3 Sf4; the double-check is essential in view of the black defenders, though the white bishop guarding g4 prevents a model mate finish. The next three twins all end with models: (b) 1.Kg6 Rd8 2.Kh7 Bf5, (c) 1.Ke4 c3 2.Kd3 Bf5, and (d) 1.Ke6 c7 2.Kd7 c8=Q. White’s only three officers form a line and disappear one by one, while the black king takes four diagonal trips to make an extended star.

OzProblems update on display of twin positions

24 Apr. 2025