Position 449

 How should White play 31 here:

If you can hit one of your opponent’s blots, you should always consider it. It may be wrong, but you should always consider. Consider 24/23* 7/4:

Black will hit you with 63, 62, 61, 52, 22, 21, 32, 43, 42, 33 and 11. That is 20 rolls or 56% of the time.

Consider hitting and making your 21 point anchor with 24/23* 24/21:

Now Black will hit you from the bar with any 4, as well as 31, 22 and 11. That is only 15 rolls, but Black will be on your 4 point threatening to anchor there. 15 rolls are a lot of rolls, is there another option? Both moves above do not really put Black under a lot of pressure. Consider not hitting at all with 8/4:

Now you are threatening to make a 5 prime, which should scare Black. Black would like to split with a 2, but 2s are duplicated to split and attack on Black’s 4 point. Black’s 4s are duplicated to attack on Black’s 4 point and to cover the blot on the 2 point.

Even if Black makes the 4 point with 42, any 2 from you from the bar, will put them behind your growing prime. If Black hits you loose on your 4 point and does not cover the blot on the 2 point, then you will hit from the bar with any 4, any 2 as well as 31 and 11. That is 23 rolls or 64% of the time.

What is hard to see here is that the non-hitting move puts Black under the most pressure.