Watch out! That tempting bit of cheese will come at a stiff price ... unless that little white mouse can somehow avoid the trap. Yes, today we're continuing our Willie Ryan series, A Trap With A Tale.

In our last excerpt from Willie Ryan's classic Tricks Traps & Shots of the Checkerboard, we showed the run-up to a position that turned out to be a Black win. The solution to that position included a computer move with which we'll see that Willie Ryan, in his book, disagreed. It's much easier to show than tell, so here goes.

This was the point at which we asked you to find a Black win. Now let's look at a possible alternate continuation, the one preferred by Willie, which he claims leads to a draw instead of a Black win.

Here the computer played 24-20 and showed a Black win, as we presented in our previous column. But Willie instead gives this to draw:

WHITE

BLACK
Black to Play, What Result?

B:W31,30,27,26,23,21,19,11:BK25,13,12,6,5,4,3,2.

Who is right, Willie or the computer? Can Black still win against Willie's preferred defense?

We think you know the answer, but can you show the Black win?

Willie stars this as the only move to draw; the computer move was instead 19-16 and White went on to lose.

Who is right, Willie or the computer? That's the question we're asking you to answer in today's column. This is probably a master-level problem, but if you followed the solution from last time, you'll have a broad hint as to what will happen here.

Take on Willie or take on the computer, and see how you do. At the heart of the position is an important over-the-board playing principle. When you're ready, click on Read More to see the solution.

Solution

Willie gave the next Black move as 6-9, and that indeed allows White a narrow draw (we'll go into that in a later column).

But Black does have a surprising win.

Do you believe this? It's the only move to win! You can hardly blame Willie for missing such an unnatural move, but it does indeed win. Carefully follow the subsequent play to see why.

Now what does White play?

Black Wins. Variations in the play are possible, but the winning idea is clear; waiting moves on Black's part make White eventually run out of viable options.

As Bill Salot said to us in an email, "Ain't computers wunnerful?"