Can you really beat blackjack
You should always split if you have a pair.
Face cards are 10 and any other card is its pip value.
And if you can memorise and / or count cards you have a real chance to walk away a winner.
For splitting, the player should always split a pair of aces or 8s; identical ten-cards should not be split, and neither should a pair of 5s, since two 5s are a total of 10, which can be used more effectively in doubling down.
(Not dealing to the bottom of all the cards makes it more difficult for professional card counters to operate effectively.).