# Switching From an S17 Chart to an H17 Table

The exact cells that change when you move from a chart where the dealer stands on soft 17 to a table where the dealer hits soft 17, deck count by deck count, plus how to practice the switch.

Source: https://21trainer.app/articles/switching-from-s17-to-h17/
Updated: October 22, 2026
Publisher: 21 Trainer, makers of Blackjack Strategy: 21 Trainer, an educational blackjack trainer for iPhone and Android (App Store: https://apps.apple.com/app/blackjack-strategy-21-trainer/id6759527695, Google Play: https://play.google.com/store/apps/details?id=app.blackjacktrainer)

> **Educational content, not gambling advice.** 21 Trainer and this article teach blackjack strategy and card counting as skills, using virtual chips only. No strategy or counting system guarantees winnings, and nothing here encourages real-money play. If gambling is a problem for you or someone you know, call 1-800-522-4700 (National Council on Problem Gambling).

You learned your chart at a game where the dealer stands on all 17s. Then you sit down somewhere new, glance at the felt, and the line reads "Dealer must hit soft 17". It can feel as if months of drilling just became worthless.

They did not. Each of the app's strategy charts holds 280 cells, and the soft 17 rule moves 6 of them in a shoe game, 6 in a double deck game and 5 in a single deck game. Every other cell you own is the same play it always was, so the job is a short list, not a restart from zero.

One catch shrinks the job further. A cell that moves does not always move your play: several of the new answers are surrenders, or splits that hinge on double after split, and when the table does not offer the option, the fallback is the play your S17 chart already taught. What you must relearn depends on deck count, on surrender, and in two cells on double after split. The lists below are exact, followed by a practice routine.

## The rule and the cost, in one paragraph

A soft 17 holds an ace counted as 11 plus six points of other cards, and it is the only dealer total whose handling varies from table to table. Under S17 the dealer stands on it; under H17 the dealer takes another card, and on balance that extra card works in the house's favor. Our [comparison of S17 and H17](https://21trainer.app/articles/s17-vs-h17/) explains why and, per the commonly published tables, puts the cost at roughly 0.2 percentage points of house edge. That article covers the rule and its cost; this one covers the chart, cell by cell.

Everything below is read from the app's own charts, fixed per deck count and soft 17 rule, so the lists are exact for those charts. One assumption throughout: doubling on any two cards; a table that restricts doubling changes more plays than the soft 17 rule does.

## Every cell the rule moves, by deck count

Here is the complete list, with where each change applies.

| Your hand | Upcard | S17 chart | H17 chart | Where it changes |
| --- | --- | --- | --- | --- |
| Hard 11 | Ace | hit | double if allowed, otherwise hit | 4 through 8 decks only |
| Hard 15 | Ace | hit | surrender if allowed, otherwise hit | one, two and 4 through 8 decks |
| Hard 17 | Ace | stand | surrender if allowed, otherwise stand | one, two and 4 through 8 decks |
| Soft 18 | 2 | stand | double if allowed, otherwise stand | two and 4 through 8 decks |
| Soft 19 | 6 | stand | double if allowed, otherwise stand | two and 4 through 8 decks |
| Soft 14 | 4 | hit | double if allowed, otherwise hit | two decks only |
| Soft 18 | Ace | stand | hit | one deck only |
| 7,7 | Ace | hit | surrender if allowed, otherwise hit | one deck only |
| 9,9 | Ace | stand | split with double after split, otherwise stand | one deck only |
| 8,8 | Ace | split | surrender if allowed, otherwise split | 4 through 8 decks |
| 8,8 | Ace | split | surrender only if surrender is allowed and double after split is not, otherwise split | two decks only |

Two rows deserve a second look. Hard 11 against an ace is absent from the two deck list because the two deck chart doubles it under both rules; only the shoe chart moves. And the hard 17 surrender against an ace is the least familiar: as our S17 versus H17 piece notes, that play exists in no S17 chart, so a player coming from S17 has never made it.

Notice where the changes sit: every changed cell is against an ace, except three soft doubles against a 2, a 4 or a 6. The relearning is one column plus a few soft cells. Our [hand by hand walk of the ace column](https://21trainer.app/articles/basic-strategy-vs-dealer-ace/) covers the rest of it, alongside our pieces on [doubling hard 11](https://21trainer.app/articles/hard-eleven-doubling/), [soft 18](https://21trainer.app/articles/soft-eighteen-blackjack/) and [double after split](https://21trainer.app/articles/das-double-after-split/).

If you play [single deck](https://21trainer.app/articles/single-deck-chart-differences/) or [double deck](https://21trainer.app/articles/double-deck-chart-differences/), those charts differ from the shoe chart in more ways than the soft 17 rule; our pieces on each cover the rest of the gap.

## Cells that move, plays that change

Count the surrender codes in the table above. At a shoe game, three of the six changed cells are surrenders, and their fallbacks are hit, stand and split: exactly the S17 answers. At a table with no surrender, the H17 chart therefore tells you to make the same three plays you already learned, and only the doubles change what you do: hard 11 against an ace, soft 18 against a 2, and soft 19 against a 6.

The same trimming works at every deck count, and the table below does it for you. It assumes doubling on any two cards, and separates double after split only where that rule decides whether a play changes, which happens twice: 8,8 against an ace in two decks and 9,9 against an ace in single deck. Our [guide to blackjack surrender](https://21trainer.app/articles/blackjack-surrender-strategy/) covers what the option is worth when a table has it.

| Decks | Double after split | Surrender | Plays that change | Which ones |
| --- | --- | --- | --- | --- |
| 4 through 8 | either | off | 3 | hard 11 vs ace, soft 18 vs 2 and soft 19 vs 6 become doubles |
| 4 through 8 | either | on | 6 | those 3, plus the hard 15, hard 17 and 8,8 surrenders vs ace |
| 2 | either | off | 3 | soft 14 vs 4, soft 18 vs 2 and soft 19 vs 6 become doubles |
| 2 | allowed | on | 5 | those 3, plus the hard 15 and hard 17 surrenders vs ace; 8,8 vs ace still splits |
| 2 | not allowed | on | 6 | those 5, plus 8,8 vs ace surrenders |
| 1 | allowed | off | 2 | soft 18 vs ace hits; 9,9 vs ace splits with double after split |
| 1 | not allowed | off | 1 | soft 18 vs ace hits |
| 1 | allowed | on | 5 | those 2, plus hard 15, hard 17 and 7,7 vs ace become surrenders |
| 1 | not allowed | on | 4 | soft 18 vs ace hits, plus the hard 15, hard 17 and 7,7 surrenders vs ace |

The spread is wide: a single deck table without surrender or double after split asks you to change exactly one play; a shoe table with surrender asks for six. Find your row before you study: drilling a surrender you will never be offered is wasted effort, and skipping one you will be offered leaves a wrong play in your game. Our [guide to which chart cells change with which rules](https://21trainer.app/articles/chart-changes-by-rule/) covers the wider discipline.

## A practice routine for the switch

Step one is to write the short list for your game, from the second table, and learn it cold. A paper list works; so do flashcards, and our [guide to blackjack flashcards](https://21trainer.app/articles/blackjack-strategy-flashcards/) describes the method precisely: three boxes, every card starts in the first, a correct answer moves a card to a box reviewed less often, a miss sends it back to the first, and each deck answers to exactly one rule set. Keep the new cards apart from any S17 cards.

Step two is to drill the affected territory: the ace column and the soft doubles against a 2, a 4 and a 6. Step three is mixed hands under the new rules, in random order, so the old reflex does not quietly return. Our piece on [mixed hand drills](https://21trainer.app/articles/mixed-hand-drills/) explains why random order tests recognizing the hand, a step that blocked practice leaves untested.

In the 21 Trainer app, set the soft 17 rule, the deck count, double after split and surrender to match the table, and the color-coded chart redraws for that game; every decision then comes with instant feedback and an explanation. The app's Single Deck and Double Deck presets both have the dealer hitting soft 17. The app cannot restrict a drill to only the changed cells or to one upcard. In the Pro upgrade, the Weakness Drill finds and drills your weakest hands, and the heat maps by hand type and upcard show whether the ace column is still weak weeks after the switch.

## Frequently asked questions

### How many plays change when you switch from S17 to H17?

It depends on the deck count and the table rules. In 4 through 8 deck games, 3 plays change without surrender and 6 with it. In two decks it is 3 without surrender, 5 with surrender and double after split, and 6 with surrender but no double after split. In single deck it ranges from 1 to 5 plays.

### Does hard 17 against a dealer ace change in an H17 game?

Yes, in every deck count the cell changes from stand to surrender if allowed, otherwise stand. That surrender exists in no S17 chart, so a player coming from S17 has never made it. If the table offers no surrender, the fallback is to stand, exactly what your S17 chart said, so such a table asks for no change here.

### Do you need to relearn the whole chart when the dealer hits soft 17?

No. The rule moves 6 cells in a 4 through 8 deck game, 6 in a two deck game and 5 in single deck, out of 280. The changes sit in the ace column, plus, in shoe and two deck games, soft doubles against a 2, a 4 or a 6. Everything else you drilled carries across untouched.

### Why does 8,8 against an ace change only in some H17 games?

In 4 through 8 deck H17 games the cell becomes surrender if allowed, otherwise split. In a two deck H17 game it surrenders only when surrender is allowed and double after split is not, and splits otherwise. In single deck the pair still splits. Without surrender, the play is a split in every deck count.

### Can you practice the H17 chart in the 21 Trainer app?

Yes. Set the soft 17 rule, deck count, double after split and surrender to match your table, and the color-coded chart redraws for that game, with instant feedback and an explanation on every decision. The app cannot restrict a drill to only the changed cells. The Pro upgrade adds a Weakness Drill that finds and drills your weakest hands, plus heat maps by hand type and upcard.

## Keep reading

- [S17 vs H17: The Small Rule With Real Cost](https://21trainer.app/articles/s17-vs-h17/)
- [Practicing for the Rules You Will Actually Face](https://21trainer.app/articles/practicing-for-a-specific-rule-set/)
- [Playing Against a Dealer Ace, Hand by Hand](https://21trainer.app/articles/basic-strategy-vs-dealer-ace/)