Re: Cover play
If we are making the "wrong" play by hitting A-7 vs. 10, then that should be our cover. I don't know what the EV is either, but if you do that, why not don't split 4,4 vs. 5,6, don't split 9,9 when appropriate, always hit or don't hit 16 vs. 10, never take insurance? I doubt any AP is going to get caught because they hit A-7 vs. 10. Most AP's get caught because they hang around too long or win too much.
Reminds me fondly of the time I split 4,4 vs. 6 and the dealer gave me a real hard time (Showboat, AC). The count was fairly high so I was betting over a hundred on each hand. Made sure I bet one black, at least one green, one red, one pink, and one white on every hand. She had to break down every hand and BJ's were particularly fun. I was being a jerk and I certainly don't recommend that strategy to anyone, but it was fun at the time.