Isn't it curious, in a world dominated by decimal numbers, undoubtedly stemming from our ten finger and ten toe makeup, that the number twelve--- a dozen--- seems to have special meaning? Arithmetic based on twelves is called duodecimal and likely arises from the approximately twelve lunar cycles that make up the solar year.
For us, the significance is that this is the twelfth column in our extended treatment of the Kelso opening, as presented in Willie Ryan's classic Tricks Traps & Shots of the Checkerboard.
We continue to look at Willie's "Variation 3." Here's the run-up.
The best move to draw remains 26-23, as Willie points out. Last time, we investigated 25-22, which is correctly analyzed by Willie to be a White loss. But what about the closely related move 26-22? Willie comments, "6-9 will do the job." We're not sure quite what Willie meant by "doing the job"; does this move win or merely give White the best winning chances?
Here's the resulting position.
In fact, there's a draw here, but White has to find it. This is probably another one of those master-level challenges, but as in previous instances, it's worth the effort and there's a lot of technique to be gleaned from a careful study of the position.
It may take more than a dozen minutes, but give it a try, and then click once (not a dozen times) on Read More to see the solution.
White will quickly regain the man.
Into the endgame database. Willie didn't have one of those!
A critical point is reached. A hasty though natural-looking 25-22 loses: 25-22 9-14 24-20 14-18 22-17 8-11 27-24 18-22 Black Wins.
Intricate and delicate endgame play follows.
Drawn. Play this one through an even dozen times; there's a great deal to be learned from it!
 Some scholars think an "even dozen" refers not to a count of exactly twelve (one dozen), but to two dozen, since two is an even number while one is an odd number. Checker Maven staff, however, won't take sides on this controversy.