Which back checker to move?

This position is a test of your sense of risk, danger, and opportunity. The wrong answer here is a huge blunder, so if you got it wrong that’s an indication you need to think again about which risks you’re willing to take and when.

24/13 gets a checker safe on the midpoint, but leaves 15 rolls that hit the remaining blot, putting White solidly into the lead. 16/5 gets a checker safely all the way round, gives you an additional builder, is much safer, and leaves you only one back checker to bring home, against a strong but inflexible board with no builders or immediate strong threat.

It’s not close. 24/13 is massively better. The biggest weakness in your game is that back checker stuck behind a 4-prime. Much better to clear it to safety (and the majority of rolls by White that miss your blot). If you leave the acepoint checker till later it will remain a weakness of your game for many moves to come.