Blackjack odds and data
Tables computed with the same engine the Veintiuno app uses: exact calculation, not simulation, with the rules and assumptions spelled out on each page.
Dealer bust probability
By upcard and by final total (17–21), for S17 and H17.
What each blackjack rule costs
How 6:5, H17, number of decks, surrender and more change the house edge.
16 vs 10, by the numbers
The expected value of hitting, standing and surrendering.
When to double down, with expected values
11 vs ace, A-7 vs 6 and every other double.
When to split, with expected values
Eights vs 10, tens vs 6, nines vs 7.
Methodology: 6 decks unless stated otherwise; the visible cards are removed and every possible card is played out (expectimax). Validated against an independent simulation of millions of hands. Details on the About page.