Position 443

 How should White play 54 here:

You notice that Black needs 4s and 2s to cover the blot on their 4 point, so you duplicate their 2s and make a point by playing 9/4 8/4:

I am a big fan of duplication, especially when I must make a bad move but sometimes it is not the most key factor.

Here you do not want Black to make their 18 point as it will exert pressure on your 13 point until you clear it. Black will make their 18 point with any 5 as well as by rolling 41 or 32 – that is 15 rolls or 42% of the time.

You start looking at the alternatives, and decide to try 13/9 6/1 which preserves your 11 pip lead:

Although this gives you a flexible position to start making points next roll, it also leaves 15 rolls or 42% of the time that Black will be able to anchor on their 18 point.

You need to disrupt their ability to anchor on the 18 point or at least limit the number of rolls they can anchor with. Consider 13/8 6/2*:

Now Black can only make the 18 point with 61, 52 or 43 – 6 rolls or 17% of the time. That is 9 rolls fewer than the previous options. Or put another way, that is 25% fewer rolls that allow Black to anchor on their 18 point.

And their 2s are duplicated to hit in your inner board and cover the blot on their 4 point.