Blackjack Strategy When Splitting a Pair of Sixes
Split: When the dealer is showing 2, 3, 4, 5 or 6
Hit: When the dealer has anything else.
Why to split a pair of sixes
When the dealer has 2 though 6 showing on his upcard, then the strategy here is to try getting him to go bust. We can use the blackjack basic strategy of the high number of 10's in play to try predicting that the total will be 12, 13, 14, 15 or 16. The dealer must hit on these numbers and have a high probability of going bust with another drawn ten. You on the other hand will have a probability of getting two 16's, which is high but not powerful.
Why to hit on a pair of sixes
If the dealer doesn't look like he's going to go bust, then the best strategy is to just take a hit on that pair of sixes totaling 12. Essentially it's the same strategy used for a hard 12.