Sometime ago there was a Blackjack game (probably ENHC) where you were dealt three cards and had to pick two starting hands, i.e. select a common card. Note in this case you know the dealer's upcard ( I created this lookup chart (AA is treated as 11), it works from 21 round to 16. It's not 100% accurate as some combinations of hand choices can't occur. You'll notice that some hands vary by the dealer upcard - e.g. 19 is better than 11 vs A789; 88 is good vs 7 but not some others.