Credits
Question 6-21 (modified) from "Back Checker Strategy" by Michihito Kageyama and Roland Herrera
XG skin design by Rain
Analysis
I keep saying it, but ‘Back Checker Strategy’ by Michy is a superb book with a hugely helpful analytical framework for how to manage your back checkers, and implications for your whole early & mid game play. Beg, borrow, or steal a copy (or buy one!).
Michy’s key proverb here won’t really make sense unless you read the book. It is ‘Leave the butterfly anchor when there is zero or one spare in the outfield’. (the butterfly anchor is an anchor on the 3 (or 22) point).
Understanding the thinking behind that proverb would lead you to the right move here, which is to run to safety with 22/13. Anything else is a blunder. Michy gives an in-depth explanation of how to handle the butterfly anchor (as well as advanced anchors, back stragglers, and more) and provides clear guidance for improving a whole area of your play. I highly recommend the book!