The Checker Maven

Lieber's Catapult

20120812-bomber.jpg

You're likely to see catapults similar to the one shown above in many an epic movie set in the Medieval period. They were fearsome siege devices; they would sling heavy rocks or other projectiles over a substantial distance in an effort to breach the defenses of the targeted castle.

In today's entry from Tricks, Traps & Shots of the Checkerboard, Willie Ryan's classic, we present an aptly-named catapult in our game of checkers. Here's Willie's run-up and very brief description.

9-14, 22-18, 5-9, 24-19, 11-16, 26-22, 7-11---A, 22-17, 16-20---2, 30-26---B

WHITE
20120812-tts102.png
BLACK
Black to Play and Win

B:W32,31,29,28,27,26,25,23,21,19,18,17:B20,14,12,11,10,9,8,6,4,3,2,1.

A---"A somewhat inferior line of play---1, but the trap at B is well concealed.

B---Caught!"

1---We're not really sure why Willie calls this move inferior, as it seems to be the best move, with the computer evaluating 10-15 as slightly worse---Ed.

2---Definitely inferior to 11-15. Perhaps Willie misplaced Note A and meant to put it here---Ed.

Can you take the leap and solve this one? While you're finding the winning Black move, spring back and correct White's losing play at 30-26. This isn't a shot in the dark; it's scientific checkers at its best. When you're finished, fling your mouse to Read More to see the solutions and detailed notes.20050904-symbol.gif



Solution

"Black now effects an artistic double-action stroke that completely throws the white formation off balance. Mike Lieber was the first player to show me this coup, back in 1925, but it may not be his.

WHITE
20120812-tts102.png
BLACK
Black to Play and Win

B:W32,31,29,28,27,26,25,23,21,19,18,17:B20,14,12,11,10,9,8,6,4,3,2,1.


20-24 6-22 11-16 27-31
27-20 23-18 28-24 22-18
11-16 4-8 22-26 11-16
20-11 32-27 31-22 7-3
8-22 8-11 16-20 31-26;
25-18 18-14 19-15 black
9-13 10-17 20-27 wins.
18-9 21-14 15-10
13-22 3-7 7-11
26-17 27-23 10-7---3

The correct move to produce a draw at B is 17-13, which leads to the following interesting situations:

BLACK
20120812-tts102a.png
WHITE
White to Play and Draw

W:W32,31,30,29,28,27,25,23,21,19,18,17:B20,14,12,11,10,9,8,6,4,3,2,1.


17-13 23-7 23-16 23-19 9-18
11-15 2-11 12-19 27-31 17-14;
18-11 25-22 27-24 19-15 drawn.
8-24 3-8 19-28 10-19 Wm. F.
28-19 26-23 31-27 17-1 Ryan
4-8* 8-12 1-5* 9-14 vs.
30-26---C 29-25 27-23 1-6 Steve
8-11 11-16* 20-24 31-26 Fair-
19-16---F 22-17---G,H 25-22 6-9 child.
12-19 16-19 24-27

C---If 25-22 is selected, the draw is developed by: 8-11, 22-17---D, 11-15, 32-28, 15-24, 28-19, 2-7*, 30-26---E, 10-15 (14-18, 23-5, 10-14, 17-10, 6-24, also produces a draw), 19-10, 6-15, 13-6, 1-10, 17-13, 15-19, 23-16, 12-19, 13-9, 19-24, 26-22, 24-28, 9-6, 28-32, 6-2, 32-23, 2-11, 23-27 (or 23-26), 31-24, 20-27, 22-17, 14-18. Wm. F. Ryan.

D---If 30-26 is played, then 10-15 paves the way for the play described in Note F; and if 22-18 is played, a draw is accomplished with 10-15, 19-10, 6-22, 13-6, 1-10, 30-26, 2-7*, 26-17, 10-15, 17-10, 7-14, 29-25, 11-16, 25-22, 16-19, etc. Wm. F. Ryan.

E---If 29-25 is moved, the following play produces a draw: 7-11, 30-26, 11-15, 19-16, 12-19, 23-16, 15-18, 26-23, 3-8, 16-12, 8-11, 12-8, 11-15, 8-3, 15-19, 23-16, 18-22, 25-18, 14-32, 16-11, 32-28*, 11-7, 10-14*, 17-10, 6-15, 13-6, 1-10, 7-2, 10-14. Wm. F. Ryan.

F---If 25-22 is chosen, the draw develops from: 10-15, 19-10, 6-15, 13-6, 1-10, 22-17 (22-18, 15-22, 26-17, 11-15, 29-25, 12-16*, 25-22, 16-19*, 23-16, 14-18, also a draw), 11-16, 17-13---I, 2-6, 29-25, 3-8, 25-22, 15-18, 22-15, 10-19, 32-28, 19-24, 28-19, 14-18, 23-14, 16-30. Wm. F. Ryan vs. A. Reisman.

G---If the move is 22-18, use this sequence for a draw: 16-19, 23-16,12-19,18-15,19-23, 27-18,10-19,18-15,19-23,15-11,1-5, 11-7, 23-27, 32-23, 14-17, 21-14, 9-27, 31-24, 20-27. Wm. F. Ryan.

H---Here's a pretty variation for a draw: 23-18, 14-23, 27-18, 16-19*, 18-15, 19-23*, 15-11, 10-15*, 11-7 (also, 22-17, 15-19, 32-28,19-24, 28-19, 9-14), 15-19, 7-2,19-24, 22-18, 24-27, 31-24, 20-27, 18-14, 9-18, 2-9, 27-31, 9-14, 12-16, 13-9, 16-19, 14-10, 23-26, 10-15, 18-22, 25-18, 1-5. Wm. F. Ryan vs. Milton Loew.

I---Or 29-25, 16-19*, 23-16, 12-19, 17-13, 2-6, 25-22, 3-8*, 22-18, 14-30, 31-26, 30-23, 27-4, 10-14, 4-8, 19-23, 8-11, 23-26, 11-7, 14-18, 21-17, 26-31, which likewise results in a draw. Wm. F. Ryan."

3---White is really trying hard, but it's hopeless---Ed.

11/10/12 - Category: Books - Printer friendly version
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