I’ve learned basic strategy from Blackjack Apprenticeship, where you should surrender hard 16 against 9, 10, A, and h15 against a 10. Just recently got the CV drills mobile app, using the BJA table, and was wondering why some additional surrenders are shown. Are these deviations? Thanks!
Picture attached below for clarification.
https://imgur.com/a/my3PpKv