Should you split 9,9? Here is the correct basic-strategy decision against each dealer upcard (6-deck, dealer stands on soft 17, DAS), from the Blackjack Theorem engine.
| Dealer | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | A |
|---|---|---|---|---|---|---|---|---|---|---|
| Play | P | P | P | P | P | S | P | P | S | S |
P = split · Ph/Ps = split if DAS else hit/stand · H = hit · S = stand · D = double
Not always. Use the table above: split (P) only against the dealer upcards shown. It's for 6-deck, S17, DAS.
Yes — double after split makes several splits correct that otherwise wouldn't be. The chart pages show DAS and no-DAS variants.