This article originally appeared in the May 2002 issue of GammOnLine.|
Thank you to Kit Woolsey for his kind permission to reproduce it here.
Have you ever witnessed the following sort of scenario:
What could be easier? Just bring them in and win. We aren't likely to win a gammon, but the game should be ours if we avoid leaving a shot. So, 9/7, 9/6. Didn't somebody once say to clear from the back and not ask any questions?
And then it happens (it always does). Out pops those double-sixes. We roll nothing special, and the cube is once again headed our way. Why does this always seem to happen to me?
Okay, that was a bit unlucky. Instead, White merely rolls a 6-5. You wind up for the kill, and pounce with ....... 6-1! An air ball. You grit your teeth and hang onto your five-prime, but of course White finds another six in his dice cup. The cube isn't headed your way immediately, but White continues to roll well while you slow up a bit and yep -- here it comes.
Another scenario. He rolls that 6-5, but this time you fire a 2-1 and get him. Of course he hits back with a three. It's only a three-point board you are facing, right? Well, it is starting to look like a 7-prime as you shake your dice to try to enter. If that other checker gets away, you will be in serious trouble.
Has this happened too often? Defeat snatched from the jaws of victory? Maybe the strategy wasn't right in the first place. After all, it's not as though you are ahead in the race. From the pip count, you are quite a bit behind. Granted White's racing lead isn't what the pip count says because White has checkers buried deep in the inner board, but losing the race is still a serious concern. Perhaps Blue should be doing something different that clearing from the back.
The proper play in the above position is not to clear the nine point. Safety is not the main issue. Containment is. The best play is 7/5, 7/4. This prepares five builders aimed at the three point in case White should run with one checker. Those nasty double-sixes are blocked. As a bonus, look what happens if White rolls 4-1 or 4-2! Now we have a good chance of closing out both checkers and getting that elusive gammon.
This sort of play is called a squeeze play. It is very often correct when the opponent has a crunched board. The idea is to force the opponent to break off his anchor without letting him escape, so you can go after him with all your guns. This play or vaiants of it come up all the time. They are unnatural-looking plays, since we are used to playing safe, but if you search for them you can find them.
Don't overdo the squeeze play. Consider the following position:
This time, the mundane 9/7, 9/6 is quite correct. Blue is well ahead in the race, and his main danger is leaving a shot in the next few rolls. In addition, he can't squeeze White off the anchor, since White has checkers to play with on the other side of the board. White will leave when he wants to leave, not before. Simply clear from that back and bring them in as safely as possible.
Is it right to break the prime before you have to? It certainly can be.
Blue can hold the fort by moving the checkers from the midpoint, but if he follows this strategy eventually he will get to a position approximating the original one. Therefore, he should start the squeeze going right now with 7/5, 7/4. It is true that this play gives White more chances to roll 4-4 and win, but it also gives White more chances to roll some other four and self-descruct.
It is important not to try the squeeze play prematurely. A small change in the position makes a big difference.
This time it is correct for Blue to hold his prime and play something like 13/11, 13/10. Breaking the bar point won't squeeze White off the anchor, since White has fours to play on the other side of the board. That would just give White a few rolls to roll the 4-4 joker. Blue could consider breaking the eight point and squeezing White with fives, but this isn't such a good idea. The problem is that White's board is too strong. If White does roll a five and scrambles with one checker, Blue will be committed to attacking even though White has the stronger inner board. That could lead to a calamity. It is better for Blue to make sure that White's board is fully crunched before he tries the squeeze play. Even though Blue may not roll as perfect a number as 3-2 in the future, he still must hold the prime for now.
When running a squeeze play, careful attention to detail is important. For the squeeze to be effective, your opponent must truly be squeezed.
White has lost his five point, so he is ripe for the squeeze play. However, 7/5, 7/4 doesn't squeeze anything this roll -- White has a four to play on the other side of the board. More effective is 8/6, 8/5, squeezing White on fives. Even though the builder distribution is better after breaking the bar point and the squeeze is more effective with fives blocked, the fact that White is immediately squeezed on fives but not on fours is sufficient to make 8/6, 8/5 the superior play.
In order for the squeeze play to be successful, you have to be ready to take advantage of it when it works.
In this position, Blue has the problem of those inner board blots. If he goes for the squeeze play and White escapes a back checker, things could get treacherous. White has as many inner board points as Blue has, and Blue could wind up second best in a blot-hitting contest. While the squeeze play will produce more gammons, of course, it is probably better to just sit on the position with 13/8.
Squeeze plays come in various shapes and varieties. If the position is ripe for the squeeze, some very unusual plays can be correct.
At first it looks as though Blue has nothing better than to bring his checkers home, and of course that is the best play to win the game. Howevever, White will probably be able to scramble off the gammon. Blue can make use of White having four checkers back and an awkward position up front to make the unusual squeeze play of 8/2, 7/1! Blue is actually hoping to be hit, so he can go back and get White on the bar against the five-point board. This play will win considerably more gammons for Blue. It could blow up in his face, but it is the percentage play.
Keeping sixes blocked is usually the right idea for the squeeze, but not always. Careful attention to details can be very important.
The best play to increase gammon chances is to break the eight point with 8/5, 8/4. The hope is that White rolls a six before he rolls an ace, and is forced to break the defensive two point and leave all three of his checkers vulnerable. Breaking the bar point and hoping that White rolls a five is not as good here, because if White rolls a six and springs the back checker Blue's gammon chances go way down and White will have improved winning chances. Blue could hold the fort with 13/10, 13/9, of course, but with White having that checker back on Blue's ace point it is worth going for the squeeze.
The farther back the enemy anchor, the less the racing danger. Consequently, the main purpose of the squeeze becomes to jar the checkers loose in order to win a gammon. Is it worth the risk? let's look at a classic position.
Is is right to break the bar point with 7/5, 7/4? That risks White rolling the 6-6 joker. If White is squeezed out with a six, Blue will still have to capture both checkers, close them out, and even after that the gammon is up in the air. Blue's pieces are placed as perfectly as they could be for the squeeze. A Snowie rollout says that the squeeze play is wrong, although very close. My guess is that Snowie doesn't play the position optimally, and that with perfect play the squeeze is probably correct. However, this is only because Blue's checkers are as well-placed as they can be to both catch a fleeing blot and pound on the remaining checker. With a less efficient structure the squeeze would not be correct, and if White had a fourth inner board point the squeeze play would definitely be wrong. However, make White's board even weaker:
Now 7/5, 7/4 is clearly correct. The loss of White's three point makes it considerably less likely that some kind of nightmare scenario will occur where Blue gets hit and flunks at a critical moment. The Snowie rollouts show the squeeze to be a substantial winner.
The more advanced the enemy anchor, the greater the danger of losing the race. Consider the following position.
Even though White still has a four-point board, it is very clear for Blue to get the squeeze on the way with 8/6, 8/3. If Blue just sits on the position, he will eventually be forced to break his prime at a moment when White will be poised to run away and win the game. White can easily win the race from the four-point anchor. It is better for Blue to go after White immediately while Blue's checkers are perfectly placed to pounce. Breaking the eight point not only wins more gammons; it also wins more games.
Coming in against a back game is always treacherous. Careful attention to detail may give you the opportunity to use the squeeze play to break up the back game.
The correct play here is to break the eight point with 8/6, 8/5. The hope is that White will roll a six other than 6-5 and be forced off the anchor on the two point. If this happens, Blue will have a much easier time coming home safely. It is true that breaking the eight point gives White the opportunity to roll a five and have excellent timing, but the chance of squeezing White off the two point makes the play correct. Note that if White had three checkers on Blue's two point and two checkers on Blue's three point, then breaking the nine point would be correct. Now, Blue would be hoping to squeeze White off the anchor on the three point.
Any time your opponent's board is crunched, be on the lookout for a profitable squeeze play. They come in all different shapes and sizes, and sometimes you have to use your imagination to find them. When you do, they can both generate extra gammons and save you from freak losses.