DSchles said:
Question: what could possibly be your options with A,A?
Well, surrendering is not allowed (not that you would want to do that anyway), since you've already split, and standing is non-sensical, as your total can only increase if you hit or double and you can't bust. That leaves hitting and doubling down as the possible reasonable options.
We normally double-down against the dealer's 5 and 6 if we have an A,2 because of the high chance of the dealer busting, so perhaps we should do the same thing for A,A. You'd need to do the math to verify this, though... and, funnily enough, while looking up "dealer bust probability calculator" to get some insight into this I stumbled upon
this blackjack calculator that shows exactly the EV of each option and, against the dealer's 5 and 6, doubling down does have a higher EV than hitting (+0.171 vs +0.169 and +0.213 vs +0.192, respectively). Against any other dealer's upcard, hitting has better EV. However, these numbers are for 2-deck S17 DAS Peek blackjack and, if you change that to 6-deck blackjack, all other rules kept the same, then, against the dealer's 5, hitting has better EV than doubling down (+0.161 vs +0.141). So, for that ruleset, you should only double down against the dealer's 6 (assuming you can't split your As, of course).
I guess that answers my question!

Only thing that's bothering me is what CVCX does in the A,A vs 5 situation. Does it adjust the strategy based on the number of decks like I've shown above or does it always double down? But that might be a topic for a different day/thread.