The Checker Maven

Thirkell's Folly

It's a "Willie Ryan" Saturday today, as we continue with our electronic republication of his classic Tricks Traps & Shots of the Checkerboard. These monthly excerpts seem to rank among our most popular columns, and with good reason: there was no one else in checker history quite like Willie; a master player who was also a most engaging writer and instructor. Here's what Willie has to say this time.

"Peter Thirkell, a prolific and talented analyst and problemist, held a prominent place as the draughts oracle of 70 years ago. But sometimes Pondering Peter, like the rest of us, pulled glaring boners. Witness his oversight in the following game, in which he passed up one of the most beautiful in-and-out shots ever to adorn the board.


10-1529-25 11-16
23-19 16-23 25-22
6-10 26-19 16-23
22-17 8-11 27-11
1-6 17-13 7-16
25-22 3-8 32-27
11-16 22-17 10-15---A
BLACK

WHITE
White to Play and Win

W:W31,30,28,27,24,22,21,17,13:B16,15,12,9,8,6,5,4,2.

A---Given by Thirkell to draw, but it loses. 8-11 or 16-20 will produce a draw easily."

Fool around with this problem all you wish, but don't be fooled; it's no folly to click on Read More to see the very fine solution.



Solution

"Continue from diagram: 22-18, 15-22, 31-26, 22-31, 24-20, 31-24, 20-11, 8-15, 28-1, 12-16, 13-6, 2-9, 1-6, 9-13, 17-14, 16-19 (4-8, 6-10, 16-20, 10-15 wins), 6-10, 19-24, 10-15, 24-27, 14-10, 27-32, 10-7, etc., and white wins."

Willie leaves it as an obvious win here, but to those of us with lesser checker powers, it may not be completely obvious. Here's the position as Willie left it.

BLACK

WHITE
Black to Play, White Wins

B:W31,30,28,27,24,22,21,17,13:B16,15,12,9,8,6,5,4,2.

The idea is that Black will, sooner or later, have to start advancing the men on 4, 5 and 13 and will eventually lose one of them. Here is a possible line of play (as computed by KingsRow with the 10-piece endgame database, with one manual edit), starting from the diagram above:

32-27 7-3 27-23 30-25 5-9 3-7 4-8 7-2 23-27 15-19 8-12 25-22 9-14 2-7 27-32 7-10

and now White wins a piece and goes on to an easy victory.

Note that Black can't simply shuffle his king around in the double corner, either, as White eventually puts an end to it. Here's one way, starting from the diagram above:

32-28 7-3 28-32 21-17 13x22 15-18 32-28 18x25 28-32 25-22 32-28 22-18 28-32 3-7 32-28 7-11 28-32 11-15 32-28 15-19 28-32 30-26 32-28 18-22 28-32 26-23 32-28 22-18 28-32 19-24 32-28 23-19 28-32 24-28 5-9 18-23 9-14 19-15 14-17 15-11 17-21 11-7 21-25 7-3 25-30 3-7 30-25 7-11 25-22 11-15 4-8 15-19 22-17 23-18 17-13 18-14 8-12 19-23 12-16 28-24 16-20 24-28

and Black is finished. The winning techniques here are well worth study as they are likely to produce many over-the-board wins for the diligent learner.

10/20/07 - Category: Books - Printer friendly version
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