H17 vs S17: What Changes When the Dealer Hits Soft 17

A single rule flip that costs the player roughly 0.22% in and changes four basic-strategy decisions. Here's the full accounting.

The Rule

In some blackjack games, the dealer stands on all 17s (known as S17). In others, the dealer hits soft 17 — any 17 that contains an ace counted as 11 (known as H17). Hard 17 is always a stand; only soft 17 varies.

The rule is usually printed on the felt in small text near the dealer's position. Finding S17 games has gotten harder over the last 20 years — most Las Vegas Strip shoe games are now H17. Downtown and off-Strip casinos are more likely to offer S17, as are most European games.

The House Edge Impact

Strategy Changes Required Under H17

Four decisions flip when moving from S17 to H17. All four make the player more aggressive — reasonable, since the dealer is now more likely to reach totals above 17.

Hand	S17 Play	H17 Play	Why
Soft 18 vs Ace	Stand	Hit	Dealer more likely to make 18+
Soft 19 vs 6	Stand	Double	Bust-out opportunity
Hard 11 vs Ace	Hit	Double	Dealer weaker on A than S17
Pair 8s vs Ace	Split	Surrender*	If surrender allowed

* The surrender change only applies in games offering late surrender. In H17 no-surrender games, pair 8s vs ace remains a split.

See the full impact across 100,000 hands.
Toggle H17/S17 in the simulator and compare win rate, drawdown, and hourly EV.

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Why This Rule Exists

Casinos adopted H17 in the late 20th century as a quiet house-edge boost. From the floor's perspective, forcing the dealer to hit soft 17 adds ~22 basis points of edge on a high-volume game — real money at scale. From the player's perspective, it's a worse game to play, but only marginally enough that most recreational players never notice.

For the counter, H17 is worse in a second way: the deviations shift slightly under H17, and the value of some side information (like tracking aces) goes up. The differences are small but real.

How to Tell Before You Sit Down

The dealer rule is printed on the table's felt, usually reading "Dealer Must Draw to 16 and Stand on All 17s" (S17) or "Dealer Must Hit Soft 17" (H17). If the felt is ambiguous or you can't see it clearly, ask — dealers and pit staff will tell you. In an online casino, the game rules are always accessible via an info button on the table.

If you have a choice between otherwise-identical S17 and H17 tables, always pick S17. The 22-basis-point difference is worth chasing.