A very complex-looking double crossing is to be found in the model railway section pictured above. We wonder, though, if it's equal in complexity to today's checker problem, which, most appropriately, arises in a line of the Double Cross opening. The Double Cross, arising from 9-14 23-18, has a bit of shall we say a checkered reputation, with 23-18 being at best a weak reply to 9-14. Nevertheless, it's completely playable if you know what you're doing, but there's plenty of opportunity to go astray.

But for now, let's jump right into our position, in which White has indeed strayed from the narrow path.

WHITE

BLACK
Black to Play and Win

B:W31,27,19,18:B11,10,9,4.

Can you find the Black win, or will you get all crossed up? Don't be cross about it; clicking on Read More brings you the solution, the run-up to the position, and the usual explanatory notes.

Solution

Here's one possible Black win against good White defense, as calculated by Ed Gilbert's KingsRow computer engine with 10-piece endgame database. There are too many variations and alternative lines to print here; we suggest you use your own computer program for further exploration.

4-8 27-23 8-12 31-26 10-14 26-22 11-16 18-15 16-20 15-10 20-24 22-18 24-27 10-6 27-31 6-1 31-26 1-5 26-22 19-15 12-16 5-1 22-26 Black Wins.

And here's the run-up to the diagrammed position.

9-14 23-18 14-23 27-18 12-16---A 18-14*---B 10-17 21-14 11-15---C 24-19 16-23 26-10 6-15 22-18 15-22 25-18 8-11 28-24 1-6 29-25 6-10 25-21 10-17 21-14 2-6 30-25 6-10 25-21 10-17 21-14 7-10 14-7 3-10 24-19 5-9 32-27---D

A---The attack with 5-9 is popular here, as is 11-15. Black has a variety of strong moves to choose from.

B---Ed Gilbert has demonstrated through computer analysis that this is very likely the only move to draw.

C---6-9 is strong here as well.

D---Loses and forms the diagrammed position. A draw can be had instead by 31-26 4-8 26-23 8-12 32-28 9-13 28-24 13-17 18-14 11-16 14-7 16-20 Drawn.