Six point primes

In backgammon primes are consecutive points made by the same player, i.e. points next to each other with two or more checkers on a point. Six point prime, or full prime is the most effective weapon known in backgammon as any opponent’s checkers are trapped behind your full prime until it is is broke. So once you’ve managed to build one, you know you are the clear favorite to win the game. Actually the question is not any more whether you aregoing to win the game, but whether you’ll be winning with a gammon.

Priming game is explained in a separate article, this article is focusing on the strategical elements of the full prime.

Attacking with a full prime

To secure the gammon, you need to move the full prime safely. To do so, you want to get as many extra checkers as possible near the prime. Usually this is not a difficult task, since having a six point prime seriously messes up your opponents game. You can just bring your back checkers forward, as it really doesn’t matter if they get hit or not - your opponent is not going to be any closer to victory as he’ll be stuck behind your prime!
When you have the extra checkers at hand and you are ready to attack, move the prime by rolling it forward. Move the checkers from back of the prime to right in front of it. This way the prime moves slowly but steadily and your opponent has very little he can do about it. Once all your checkers are on your home board, bear them off the board as usual.
Always be aggressive when you have a six point prime. As explained above, being hit is not a real concern as the opponents checkers will remain stuck behind your prime. Sometimes it even is optimal to get hit and spend a few turns on the bar watching how your opponent’s game breaks down as he can’t move his back checkers. The only way your prime can break down is when you can’t move your extra checkers and you are forced to break the prime. The key to limit the chances of having to break your full prime is to always move your back checkers forward towards the prime when ever you can.

Note on doubling

If you have a good game going on and it looks as if you can build a six point prime in a few turns, double! If you double once you have created your full prime you are too late - your opponent will just resign. And of course that’s something you don’t want because a full prime gives you a great chance to win with a gammon.

If you failed to double before you made a full prime, don’t double any more but just keep on playing. You are likely going to win the game so go for the points you can get. And who knows, perhaps you’ll even be able to score a backgammon!

Defending against a six point prime

Be sure you know what to do if your opponent builds a six point prime, because that’s pretty much the worst that can happen to you. You must concentrate on building your back game and making points on your home board. This way you are ready to make the most of it when to opportunity arises to hit a blot.Back game is explained in a separate article, we’ll just have a look at a few important elements.
You don’t want to hit if you will be still behind the six-point prime after hitting! See, if you go an hit your opponent’s checker and your opponent will spend a couple of turns on the bar, you will very likely be forced to move your checkers on your homeboard and as a result nicely break your homeboard setup. However, if hitting breaks your opponent’s six point prime and you’ll have only a 5-point prime to tackle, go for it! That could be your last chance to win the game.

You can also consider hitting, if you have a strong home board. By strong I mean that you have something like points 2-5 secured. This way there is always a small chance that after your opponent’s checker enters from the bar once you have hit it, he’ll roll small numbers and he will be the one who will eventually have to break his prime. This situation is quite rare and you really need to be careful to decide whether hitting is worth the risk.

Finally, unlike in a case of a smaller blockade, you don’t want to leave your checker right in front of the prime! Leaving a blot in front of a six point prime is a great way of getting steamrolled. If the checker right in front of the prime gets hit, you could be witnessing the the following scenario: your blot in front of the prime gets hit, you spend a turn on the bar, your opponent makes the point, you spend a turn on the bar, your opponent makes another point etc. So take my word for it and avoid leaving a blot in front of your opponent’s six point prime and focus on getting your back game together.

In short: if you have been caught behind a full prime, the best thing you can do is to make a point right in fron of it and slowly build your home board and to hope that luck is on your side. Thats really all there is to it - the best way of defending against a six point prime is to never allow your opponent to build one!

Conclusions

If you have even the slightest chance of building a six point prime, take it! It will not only win the game for you, but it will also drive your opponent mad at the same time. Playing behind a prime is the most frustrating situation possible in backgammon. And that’s why you should attack with full force if you notice your opponent slowly getting his six point prime together! If you can muster up any kind of an offensive maneuver, do so. You want to fight the prime before it is build, not after.