So you've built your full prime, but your opponent managed to anchor behind it. Now what? Of course you have to do the following:

1. bring the remaining checkers (not in the prime) home
2. bear all checkers in safely

It's hard to make large blunders doing this, but I do see XG marking me down for small errors. How should I be thinking about these kinds of positions?

Here is a concrete position:


Here I played 16/14 11/9. XG prefers 16/13 11/10 by 0.026. It appears that this is to avoid a 1-1 joker after 16/14 11/9 (White hits both checkers and covers, trapping 2 Black checkers behind a 5-prime).

A few rolls later in the same game, this position is reached:


Here I played 11/7 9/3, but XG prefers 9/5 7/1 by 0.033. What's the reason for this? Is it just the general principle to avoid stacking your checkers? When I don't see an obvious difference, usually I just bear-in from the outside in. I even once ran into a position where XG said the best play was to break the prime from the middle (something like the 7-point on a prime from 4 to 9) but I can't find it now.

In your first problem, there is no good reason to get a checker hit. If you leave blots and White hits, you may lose the prime against prime battle. No reason to allow that.

In problem 2, you always want to keep your three spares on different points if you can, so you will have the most choice in how you play your next roll.

Thank you, that was helpful.