We're not talking today about the city of Denver, as attractive and appealing as that modern metropolis might be. Instead, we're talking about John Denvir (and neither do we mean the late popular musician who called himself John Denver). John T. Denvir was a well-known checker player and author in the early 1900s, and was, to put it mildly, a man of controversy. He did publish a number of checker instruction books, and today's two-part problem is drawn from one of them.
First, look at this position arising from a Single Corner opening:
White has drawing moves here, and it's not so hard to find them. We invite you to give it a try.
One way not to draw is with the seemingly clever 20-16, which results in this position.
Can you find a win for Black at this point?
If you don't find the solutions, you needn't travel all the way to Denver to see how it's done; clicking on Read More will transport you immediately to the answers.
In the first diagram, White can draw in a couple of ways. One possibility is 9-5 14x23 5-1 23-26 22-18 26-30 1-5 2-7 5-9 30-26 18-14 etc., drawn. Another way is 22-17 14x23 9-5 23-27 17-14 2-7 14-9 27-31 9-6 31-27 5-1 27-23 6-2 23-18 20-16 11x20 2x11 18-23 11-15 20-24 etc., to an eventual draw. Variations in both lines are of course possible; you can use your computer to review them.
In the second diagram, Black wins as follows: 11x20 18-15 20-24 15-11---A 24-27 11-8 27-31 8-4 31-26 9-5 26x17 4-8 2-7 5-1 14-18 1-6 18-23 6-2 7-10 2-6 10-14 8-11 and Black wins easily.
A---If instead 9-5 then 24-27 5-1 27-31 1-5 31-26 5-9 26x17 9x18 2-7 18-23 17-14 15-10 14-9 and Black wins.