The ace is the strongest upcard in blackjack. Per the final total distribution tables computed by Wizard of Odds for six decks with the dealer standing on soft 17, a dealer showing an ace who has already been checked for blackjack busts only 16.7 percent of the time, the lowest bust rate of any upcard. Our piece on what the dealer actually ends up with lays out the full tables.
The ace column is also the most rule sensitive in the chart: nowhere else do so many cells flip with the soft 17 rule. This article walks the column cell by cell, continuing our walks through the 2 column, the 6 column and the 7 column.
Table conditions throughout, matching the app's standard shoe chart: dealer peeks, blackjack pays 3:2, double on any two cards, late surrender where offered, four to eight decks, dealer stands on soft 17 unless stated.
The whole column, one table
| Your hand | Play against a dealer ace |
|---|---|
| Hard 8, 9 and 10 | Hit |
| Hard 11 | Hit |
| Hard 12 through 15 | Hit |
| Hard 16 | Surrender if allowed, otherwise hit |
| Hard 17 and up | Stand |
| Soft 13 through soft 18 (A,2 through A,7) | Hit |
| Soft 19 | Stand |
| Soft 20 | Stand |
| 2,2 3,3 4,4 6,6 7,7 | Hit |
| 5,5 | Hit (it is a hard 10, and hard 10 hits against an ace) |
| 8,8 | Split |
| 9,9 | Stand |
| 10,10 | Stand |
| A,A | Split |
One note: no hand doubles against an ace in this chart; a section below takes up hard 10 and 11.
How the six charts move this column
The shoe chart above is the baseline across the app's six charts (one and two decks, and four to eight decks, under both soft 17 rules); here is everything that moves.
| Hand | What changes, and in which charts |
|---|---|
| Hard 11 | Double if allowed, otherwise hit, in every chart except the 4 to 8 deck chart where the dealer stands on soft 17 |
| Hard 15 | Surrender if allowed, otherwise hit, in all three charts where the dealer hits soft 17 |
| Hard 17 | Surrender if allowed, otherwise stand, in all three charts where the dealer hits soft 17 |
| Soft 18 | Stand in the one deck chart where the dealer stands on soft 17 only |
| 7,7 | Surrender if allowed, otherwise hit, in the one deck H17 chart only |
| 9,9 | Split if double after split is allowed, otherwise stand, in the one deck H17 chart only |
| 8,8 | 4 to 8 decks, dealer hits soft 17: surrender if allowed, otherwise split. Two decks, dealer hits soft 17: surrender if surrender is allowed and double after split is not, otherwise split |
Everything else in the column is identical across all six charts; our comparison of S17 versus H17 prices the rule overall.
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The peek, insurance, and even money
These charts assume the dealer peeks, as our piece on the peek rule explains: when the upcard is an ace or a ten, the dealer checks the hole card before anyone acts, and a blackjack ends the hand immediately. So by the time you decide, the dealer does not have blackjack, which is why the outcome tables quoted here exclude dealer blackjacks.
Insurance is declined every time, as our piece on why basic strategy never takes insurance works through: the bet pays 2 to 1 and is fair only if the hole card is ten valued one time in three, and ten valued cards make up only 30.8 percent of a full deck. Even money on your own blackjack is the same bet settled early.
Under the no hole card arrangement described in our article on European blackjack, a late dealer blackjack can sweep doubled and split bets, so the commonly published charts for that game turn doubles against a ten or an ace into plain hits and avoid splitting 8s against them, though most keep splitting A,A against an ace.
Soft 18 hits, and one chart where it stands
Many players stand on soft 18 everywhere, and our soft 18 guide counts the ace, with the 9 and 10, among the upcards where that habit costs the most. Run the standing arithmetic with the S17 table: a standing 18 against an ace wins when the dealer finishes on 17 or busts, 18.8 plus 16.7 for 35.5 percent, pushes the 18 for another 18.9, and loses to 19, 20 and 21 combined, 18.9 plus 18.9 plus 7.7 for 45.5 percent. Standing loses more often than it wins.
Hitting does not have to win more often than it loses to be correct; it has to lose less than standing, with a structural comfort: a soft 18 cannot bust on one draw, because the ace drops back to 1. The one deck chart where the dealer stands on soft 17 stands instead: a close decision the chart resolves the other way in that game.
The surrender arithmetic: 16 always, 17 when the dealer hits soft 17
Hard 16 surrenders against an ace in all six charts, and the case against standing takes one line of arithmetic. A standing 16 wins only when the dealer busts, 16.7 percent with the dealer standing on soft 17, and loses everything else: about 0.167 minus 0.833, roughly -0.67 units per unit bet against the certain -0.5 from surrender. The chart's fallback when surrender is not offered is to hit, not to stand; the value of hitting is a longer computation than this table supports, so the table settles only the stand versus surrender comparison, and that one is not close.
Hard 17 is the cleaner lesson: the same arithmetic flips with one rule. With the dealer standing on soft 17, a standing 17 wins only on the bust, 16.7 percent, and pushes when the dealer makes exactly 17, 18.8 percent, and loses the rest, 18.9 plus 18.9 plus 18.9 plus 7.7 for 64.4 percent. That is about 0.167 minus 0.644, or -0.477 units, better than the fixed -0.5 of a surrender, so 17 stands. With the dealer hitting soft 17 the row shifts: win 20.1 on the bust, push 8.3, lose 71.6 (20.7 plus 20.7 plus 20.7 plus 9.5), about 0.201 minus 0.716, or -0.515, slightly worse than -0.5, so 17 surrenders. All of these figures, like the soft 18 ones above, are approximate arithmetic from the published table, not exact expected values, and the table ignores the small effect of the player's own cards on the dealer's draw. The 17 row is the cleanest illustration in this series of a single rule flipping a cell.
Why nothing doubles, and the pairs that still split
Hard 11 and hard 10 have the widest doubling windows among the hard totals, and neither doubles against an ace in this chart. Hard 11 is a close decision the rules tip; hard 10 hits against an ace in all six of the app's charts. For hard 11, our piece on doubling hard 11 puts it plainly: in a game where the dealer stands on soft 17, the extra bet does not quite earn its place against an ace, so the chart takes the draw without the extra money. For hard 10, the hard 10 doubling guide says the same from the other side: the second bet does not pay for the dealer's most powerful upcard.
The pair rows thin out the same way, with two famous exceptions. 8,8 still splits, and the framing in why you always split aces and 8s is honest about what that means: against a strong upcard, splitting 8s is a losing play that loses less than a hard 16, which is basic strategy's whole job in this column. A,A splits too: a pair of aces is a soft 12 going nowhere, while each split ace starts from the best opening card in the game. The surrender-instead-of-split cells in the four to eight deck and two deck hit soft 17 charts are that same comparison taken one step further.
The rest of the pairs are quiet. 9,9 stands: it is a hard 18, split only in the one deck H17 chart, and then only with double after split. 10,10 is a made 20 that loses only to the dealer's 21, 7.7 percent in the S17 table. And 5,5 is not a pair decision at all: it is a hard 10, and hits for that reason.
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Frequently asked questions
Should you hit 16 against a dealer ace?
In the standard shoe game where the dealer stands on soft 17, hard 16 surrenders if the table allows it and hits otherwise. A standing 16 wins only when the dealer busts, about 16.7 percent of the time per the published dealer tables, which averages far worse than the fixed half bet loss a surrender accepts. Without late surrender, the chart falls back to hitting.
Do you split 8s against a dealer ace?
Yes, in most games. Two 8s together are a hard 16, the worst total in the game, and two hands starting from an 8 lose less than that one hopeless hand even against the strongest upcard. The exceptions come where the dealer hits soft 17 and late surrender is offered: four to eight deck games surrender the pair, and two deck games surrender it when double after split is not allowed.
Should you take insurance when the dealer shows an ace?
No. Insurance is a separate bet that the hole card is ten valued, and it pays 2 to 1, which is fair only if that happens one time in three. Ten valued cards make up only about 30.8 percent of a full deck, so basic strategy declines every time, and even money on your own blackjack is the same bet in a different costume.
What do you do with soft 18 against an ace?
Hit, in five of the app's six charts. When the dealer stands on soft 17, a standing 18 against an ace wins only when the dealer finishes on 17 or busts, 18.8 plus 16.7 for 35.5 percent, and loses to 19, 20 and 21 combined, 45.5 percent. A soft 18 also cannot bust on one draw, because the ace drops back to 1. Only the one deck chart where the dealer stands on soft 17 stands instead.
Why does 11 hit instead of double against an ace?
In a shoe game where the dealer stands on soft 17, the ace is strong enough that the second bet does not quite earn its place, so the chart hits, keeping the money exposure lower while still building the hand. The decision is close, and the rules tip it: switch to a hit soft 17 game, or one or two decks, and hard 11 doubles instead.