Problem of the Week #20: July 19


Cash game. Center cube. Black on roll.



Part (a): Black to play 5-2.



Part (b): Black to play 4-2.


In backgammon, most hits are done for one of two reasons: to gain ground in the race, or to attack a key point. A rarer (but still important) use of the hit is a defensive idea called the tempo play. Here the plan is to prevent your opponent from using his whole roll to do something good. By hitting (usually in your home board), you force him to spend half his roll coming in from the bar, so he’s not in position to do something devastating elsewhere on the board.

Part (a) shows a common situation where beginners make a tempo hit incorrectly. White has won the opening roll with a 6-3 and run his back checker to the outfield. Black now rolls an innocuous 5-2. Many beginners will go astray here and play 6/1* 24/22. Since it’s a hit, the play looks somewhat active and aggressive, but it actually doesn’t accomplish anything. White had no powerful threats that Black needed to stop, and the checker left on the one-point is both immediately vulnerable and a long-term liability. A better play is the simple 24/22 13/8. It does a few good things (unstacks the midpoint, adds another builder to the 8-point, and splits the back checkers), but most important, it doesn’t do any bad things.

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Part (b), on the other hand, shows a very different situation. Black is ahead in the race and hence has less timing than White. This means that Black will actually have to escape White’s prime: waiting for it to collapse is not an option. If Black is going to escape, he’ll need to throw a two at some point, and – guess what – he’s just thrown one. So there’s a really strong case for playing 23/21 with the deuce.

Once the checker gets to the 21-point, White, if left alone, will point on it, or at the very least hit loose. Black needs a diversion to keep the dogs at bay, and 5/1* fits the bill perfectly. It has an added bonus (don’t miss this) of winning more gammons for Black than any other play. It’s true that shoving what was a nice builder down to the ace-point weakens Black’s chances for a full prime, but changing a priming game into a sudden blitz is often the right strategy, especially when neither side has an anchor.

The difference between these two positions is simply the amount of immediate danger that Black faces. You don’t like to hit loose deep in your home board, both because getting hit back is usually costly, and because the checker becomes a future liability even when it isn’t hit. So to make the hit correct, you need to be facing very serious threats. In Part (b), White has those threats; in Part (a), he doesn’t.

Solutions: Part (a) 13/8 24/22.

Part (b) 23/21 5/1*.

Well said.

Ok...all theory has changed since I last played then. I spent 20 man hours analyzing responses to opening rolls back in the day and obviously those were wasted to come up with beginner mistakes...("the day" is overrated i guess)

Back to poker I guess

I wouldn't say "all theory" has changed since ... (the 1980s, I'm guessing?) but our knowledge of how to play the openings is way more precise than it was back then. Hitting on the ace-point with a 5 was a common response in those days in positions like 20a. Now we really only hit on the ace if our opponent has split to the bar point, because then the hit has a real bite: it prevents him from anchoring on the bar and gives him awful sixes in return, a payoff which is worth the risk.

snowie liked the loose hit better before rollouts fwiw

2 for 2. Part a answer was from continually being told off by the GNU tutor for 6/1 though