Black – Pips 116 (-7)
Black to Play 3-2
This position comes from the late middle game. White is on the bar without an anchor, falling behind in the race and in some danger of being closed out. Meanwhile Black has a couple of checkers stuck behind a 4-prime. Black needs to escape but he needs to close his board as well, so he’s under constant pressure each turn to get something done.
Black throws 3-2, which isn’t much of a roll – he can’t cover and he can’t escape. He has only two plausible plays:
Play A: 8/5 8/6, dismantling the 8-point but creating cover numbers for the 2-point.
Play B: 13/10 13/11, keeping the 8-point while also generating some extra cover numbers.
A static analysis clearly points to 8/5 8/6 as being the best play. It yields more cover numbers for the 2-point (26, as opposed to 22 for 13/10 13/11). It gives White fewer shots from the bar (11, as opposed to 13 for Play B). It leaves fewer blots (one, instead of three). And it diversifies Black’s numbers (he needs 3s and 4s to cover the 2-point, 5s and 6s to hop the prime.) Wow! Clearing the 8-point should be a no-brainer, right?
Well, not quite. Clearing the midpoint has a couple of other factors in its favor, factors which are more subtle and harder to quantify, but equally important.
The first consideration is the strength of owning the 8-point. With a blot on the 2-point, the 8-point retains considerable blocking value in case White throws a deuce from the bar.
The second and more important consideration is what I like to call playability. A playable position is simply one which has spares to move when you need them. It’s the opposite of a stripped position, where you don’t have any extra men, and you’ll need to break a point next turn. When you have a stripped position without anything concrete to do, a play which breaks a non-vital point and creates a couple of spares is often good all by itself.
In this position both of Black’s choices create some playability. Breaking the 8-point gives Black two spares on the 5-point and 6-point. Breaking the midpoint gives him spares on the 10-point and 11-point. The amount of playability differs, however. If we assume Black has no interest in moving checkers beyond his 2-point, then the spares on the 5-point and 6-point represent only 7 pips of playability. The spares on the 10-point and 11-point, on the other hand, account for 17 pips of playability – more than twice as much.
Note also that the spares in the outer board can play any number Black might throw next turn, while the spares in the inner board can only usefully play fours or less. This becomes a big deal if White hits from the bar and Black responds with a small number plus a big number: 1-5, 2-5, 1-6, or 2-6. These numbers play well if Black’s spares are on the 10-point and 11-point, but they’re horrible if Black has played 8/5 8/6 instead.
So what’s right? Does the extra “playability” of 13/10 13/11 trump the static advantages of 8/5 8/6? In this case they do, and in fact I don’t think most good players would have a hard time with this problem. The position after 8/5 8/6 looks a little peculiar. Having no checkers in Black’s outer board is liable to cause some sort of problem with Black having checkers so far back. By comparison, the position after 13/10 13/11 looks much more natural and easier to play. The difference between the two plays isn’t huge; clearing the 8-point is certainly not a major blunder. But it does make Black’s position more fragile, and disaster can come quickly to fragile positions.
