Blackjack Trainer: 21 Coach

Soft 20 vs dealer 10: hit or stand?

Stand. Soft 20 against a dealer 10 is played the same way whether the dealer hits or stands on soft 17.

Why

An ace hand this high already beats most of what the dealer finishes with. There is no card that improves it often enough to be worth the swap.

Soft 20 means an ace is counted as 11 without busting. With two cards it is an ace and a 9.

The numbers

How a dealer 10 finishes (6 decks, after the dealer has checked for blackjack; rounded)
Dealer rule1718192021Bust
Either dealer rule12%12%12%37%4%23%
Average result per hand for each play (6 decks; higher is better)
PlayEither dealer rule
Stand+0.55best
Hit+0.02
Double down-0.02
Surrender (where offered)-0.50

Scoring: a win scores +1, a loss -1, a tie 0, and a doubled hand counts twice. Surrender scores -0.50. Hit means take a card, then play on as well as possible. These are averages over many hands from the strategy audit behind the app, rounded and approximate. Any single hand can go either way.

Rules assumed

One-deck and two-deck games, tables without surrender, and dealers who do not check for blackjack change some plays. Check your table's rules before relying on any chart.

Both soft 17 rules are shown. The two charts differ on only 6 of 360 hands: see the dealer hits and dealer stands charts. The plays come from the verified 4 to 8 deck tables behind the Blackjack Trainer app (bs_4to8_h17_peek and bs_4to8_s17_peek).

Common questions: Soft 20 vs dealer 10

What is the correct play for soft 20 against a dealer 10?

Stand. This is basic strategy for 4 to 8 decks, and it is the same whether the dealer hits or stands on soft 17.

Does the soft 17 rule change soft 20 against a dealer 10?

No. The play is the same whether the dealer hits or stands on soft 17. Only a handful of hands on the chart change with that rule, and this is not one of them.

Why stand with soft 20 against a dealer 10, and not hit?

An ace hand this high already beats most of what the dealer finishes with. There is no card that improves it often enough to be worth the swap. Average result per hand over many hands (a win scores +1, a loss -1): when the dealer hits soft 17, standing scores +0.55 and hitting scores +0.02; when the dealer stands on soft 17, standing scores +0.55 and hitting scores +0.02.

Does the play change if soft 20 has more than two cards?

No. This chart uses only your total and the dealer card, not how many cards made the total. Exact card makeup can shift a few close calls by a fraction of a percent, which is why basic strategy ignores it.

Does this assume the dealer has already checked for blackjack?

Yes. In US-style games the dealer checks for blackjack when showing a 10 before you act, so this play applies once the dealer is known not to have one. In games where the dealer does not check, some plays change.

Does basic strategy guarantee a win?

No. It picks the play with the best average result, but any single hand can go either way, and the house keeps a small edge. This site and the Blackjack Trainer app are for practice only.