Lets assume you are playing black in the position above. Would you double? If you where white would you take if you are doubled?
Beginners and many intermediate players have problems with positions like this. What usually happens is they roll something like 62, play it 15/7 and then after white rolls an average number – 53 for example played 17/9, black doubles and white will pass..
They do not double before the roll because the players are thinking along the lines of : “I am not favorite to get that checker on my 15-pt to safety and then if it does get hit white will have such a strong board that I will have to pass his redouble – I think I shall wait.”
Now let us take a look at how to think about this position in the correct manner. . You must first check the three key elements of doubling:
The Race – black is ahead by 17 pips before the roll so based on the race alone this is a pass. Advantage lies with black
Position – black has a 4½ point home board as opposed to white’s five point board. Slight advantage to white.
Threat – black has some big threats. He could make the point on white’s blot on his 5-pt. He could hit the white blot on his 8-pt and not be hit back at all. . He could bring his last checker to safety. He could roll a big double. These threats are immediate so the position is highly volatile. Big advantage in black favor.
The rule of thumb is that if you are ahead in two of the three elements then you should at least be considering the double. It should therefore be obvious that black has a powerhouse double.
Waiting until your opponent has a clear drop is not the way to maximise your equity when playing backgammon. You must double when you threaten to lose your market by the time it is your turn to roll again. You will lose some games in which you have doubled – that lies in the very nature of backgamon and that is what makes it such a great game in the first place. If however, you double at the right moment, then you will win lots more two-pointers and four-pointers.
Should white take the double? If white estimates that he can win approximately one game out of four then he should be taking the double. Most good players will be able to judge from past experience that this is a take. A lot of the time when black hits, e.g. 52 played 15/8*, then white will have the possibility of immediate return game winning shots and in some cases he will win a gammon if he can hit and close out two of black’s men. It’s impossible to count all the hitting sequences but white will get a single shot (which he has a 30% chance of hitting) often enough to make this a comfortable take. Thus the position is both a correct double and a correct take as evidenced by the rollouts shown below.
Just out of interest , how would you play 32 as black after double/take? I hope you would play 7/5*, 6/3 despite the fact it will leave three blots. 6/4, 6/3 would be a huge error. 7/5*, 6/3 will win many more games and many more gammons than 6/4, 6/3. And yes you will occasionally lose a gammon by making this play but as stated earlier that’s part of the game.