--- title: "ATs vs A9s: preflop equity" url: "https://georgelipoker.com/equity/ats-vs-a9s.md" canonical_url: "https://georgelipoker.com/equity/ats-vs-a9s" last_updated: "2026-10-23" type: "reference" summary: "ATs is a big favorite over A9s before the flop: 69.15% to 30.85% equity, counted exactly over every board, with the split by flop type and suit." related: ["https://georgelipoker.com/equity/ats-vs-ato.md", "https://georgelipoker.com/equity/ats-vs-kjs.md", "https://georgelipoker.com/equity/aqo-vs-a9s.md"] --- # ATs vs A9s: preflop equity ATs is a big favorite over A9s before the flop: 69.15% to 30.85% equity, counted exactly over every board, with the split by flop type and suit. The exact count puts ATs at 69.15% and A9s at 30.85% when the two hands see all five board cards. ## ATs against A9s: the numbers **Exact preflop results for ATs against A9s, in percent** | Hand | Wins | Ties | Loses | Equity | | --- | --- | --- | --- | --- | | ATs | 64.346 | 9.611 | 26.043 | 69.151 | | A9s | 26.043 | 9.611 | 64.346 | 30.849 | ATs meets A9s, and both are suited hands. Sharing a rank is the signature of a dominated hand, since the weaker hand is usually out-kicked when the shared rank shows up. ATs is well ahead, and A9s needs a specific kind of board to catch up. Ties are part of the picture: 9.61% of boards end in a split pot, and each side counts that as half a win. ATs ranks number 13 of 169 starting hands, and A9s ranks number 18, by equity against a random hand. **Boards behind the percentages: 20,547,648 counted in all** | Hand | Boards won, about | Boards tied, about | Boards lost, about | | --- | --- | --- | --- | | ATs | 13,222,000 | 1,975,000 | 5,351,000 | | A9s | 5,351,000 | 1,975,000 | 13,222,000 | Exact total: 12 deals times 1,712,304 boards. The other three counts come from the five-decimal percentages and are rounded to the nearest thousand, so read them as approximate. **ATs against A9s read as odds** | Hand | Equity as odds (to 1) | Wins one deal in | Loses one deal in | Pot odds needed to call (to 1) | | --- | --- | --- | --- | --- | | ATs | 2.242 | 1.554 | 3.840 | 0.446 | | A9s | 0.446 | 3.840 | 1.554 | 2.242 | In the last column, a pot-to-call ratio at or above the figure makes a call break even or better at this equity. ## Who is ahead on which flops If you know the kind of flop that came, the numbers shift: ATs holds 75.12% on rainbow flops topped by a ten or better and 61.48% on low rainbow flops (nine high or lower). ATs stays ahead on all five textures. **ATs against A9s by flop texture, in percent** | Flop | Share of flops | ATs wins | Ties | A9s wins | ATs equity | | --- | --- | --- | --- | --- | --- | | Rainbow, ten or higher | 23.867 | 70.974 | 8.281 | 20.745 | 75.115 | | Rainbow, nine or lower | 7.042 | 59.455 | 4.046 | 36.499 | 61.478 | | Two-tone | 46.543 | 65.804 | 6.593 | 27.603 | 69.100 | | Monotone | 5.215 | 59.676 | 7.666 | 32.658 | 63.509 | | Paired | 17.333 | 54.697 | 22.392 | 22.911 | 65.893 | Read the flop types this way: rainbow has three suits, two-tone has two cards of one suit, monotone has three, and paired repeats a rank. ## Compared with a random hand The table below sets each hand against its own random-hand baseline: a change of +4.55 points for ATs, from 64.60%, and -31.93 for A9s, from 62.78%. **ATs and A9s here compared with each against a random hand, in percent** | Case | Equity here | Against a random hand | Change in points | Times the random-hand equity | | --- | --- | --- | --- | --- | | ATs, all flops | 69.151 | 64.602 | +4.549 | 1.07042 | | ATs, rainbow, ten or higher | 75.115 | 64.602 | +10.513 | 1.16273 | | ATs, rainbow, nine or lower | 61.478 | 64.602 | -3.124 | 0.95164 | | ATs, two-tone | 69.100 | 64.602 | +4.498 | 1.06963 | | ATs, monotone | 63.509 | 64.602 | -1.093 | 0.98308 | | ATs, paired | 65.893 | 64.602 | +1.291 | 1.01998 | | A9s, all flops | 30.849 | 62.781 | -31.932 | 0.49137 | | A9s, rainbow, ten or higher | 24.885 | 62.781 | -37.896 | 0.39638 | | A9s, rainbow, nine or lower | 38.522 | 62.781 | -24.259 | 0.61359 | | A9s, two-tone | 30.900 | 62.781 | -31.881 | 0.49219 | | A9s, monotone | 36.491 | 62.781 | -26.290 | 0.58124 | | A9s, paired | 34.107 | 62.781 | -28.674 | 0.54327 | ## Does a shared suit matter? Every legal deal of ATs against A9s leaves the hands with no suit in common, so the suit split does not apply here. **ATs against A9s by suit overlap, in percent** | Deals | Specific deals | Share of deals | ATs wins | Ties | A9s wins | ATs equity | | --- | --- | --- | --- | --- | --- | --- | | Share a suit | 0 | 0.00 | not possible | not possible | not possible | not possible | | No shared suit | 12 | 100.00 | 64.346 | 9.611 | 26.043 | 69.151 | ## How often this matchup comes up Out of 1,624,350 ways to deal two seats two cards each, 12 are ATs in one seat and A9s in the other (0.0007%); with the seats swapped too, 24 (0.0015%). ## A worked example Say each player puts $100 in before the flop, making a $200 pot. On average ATs takes back $138.30 of it, which is $38.30 more than it put in, and A9s takes back $61.70, $38.30 less than it put in. Over a long run, 1,000 deals split into about 644 for ATs, 260 for A9s and 96 tied. ## The same matchup from the other side The mirror image, A9s against ATs, is 30.85% to 69.15%, and its address redirects to this page. ## Keep exploring Try AsTs against Ah9h in the calculator: the hands share no suit, and every card can be changed. The links after it are the closest matchups in the ranking. - [Open AsTs against Ah9h in the equity calculator](https://georgelipoker.com/tools/equity-calculator.md#p1=AsTs&p2=Ah9h) - [ATs combos](https://georgelipoker.com/combos/ats.md) - [A9s combos](https://georgelipoker.com/combos/a9s.md) - [ATs vs ATo](https://georgelipoker.com/equity/ats-vs-ato.md) - [ATs vs KJs](https://georgelipoker.com/equity/ats-vs-kjs.md) - [AQo vs A9s](https://georgelipoker.com/equity/aqo-vs-a9s.md) - [All hand matchups](https://georgelipoker.com/equity.md) ## How this was computed We counted every case. Each suit pattern of the 12 specific ATs against A9s deals meets all 1,712,304 boards, and the better five-card hand wins; a split pot is half a win each. The flop table reads each board under all ten of its three-card flops. Source: our own exact count from the GeorgeLiPoker poker math library. No outside data is used. ## Related - [ATs vs ATo: preflop equity](https://georgelipoker.com/equity/ats-vs-ato.md) - [ATs vs KJs: preflop equity](https://georgelipoker.com/equity/ats-vs-kjs.md) - [AQo vs A9s: preflop equity](https://georgelipoker.com/equity/aqo-vs-a9s.md)