--- title: "A9s vs 55: preflop equity" url: "https://georgelipoker.com/equity/a9s-vs-55.md" canonical_url: "https://georgelipoker.com/equity/a9s-vs-55" last_updated: "2026-10-23" type: "reference" summary: "A9s vs 55 is close to a coin flip before the flop: 47.50% to 52.50% equity, counted exactly over every board, with the split by flop type and suit." related: ["https://georgelipoker.com/equity/a9s-vs-qjs.md", "https://georgelipoker.com/equity/a9s-vs-k9s.md", "https://georgelipoker.com/equity/ato-vs-55.md"] --- # A9s vs 55: preflop equity A9s vs 55 is close to a coin flip before the flop: 47.50% to 52.50% equity, counted exactly over every board, with the split by flop type and suit. If 55 and A9s get all the chips in before the flop, 55 owns 52.50% of the pot in the long run and A9s owns 47.50%. ## A9s against 55: the numbers **Exact preflop results for A9s against 55, in percent** | Hand | Wins | Ties | Loses | Equity | | --- | --- | --- | --- | --- | | A9s | 47.262 | 0.476 | 52.262 | 47.500 | | 55 | 52.262 | 0.476 | 47.262 | 52.500 | A9s, a suited hand, plays 55, a pocket pair. A pair against two higher cards is the classic race: the pair is usually a small favorite or close to even, and each overcard that pairs is a way to take the lead. With only 5.00 points between them, the board decides this matchup far more than the cards in hand. A split pot comes up on 0.48% of boards, so the wins and the equity differ by half of that. For context, A9s sits at number 18 of 169 starting hands and 55 at number 27 when each is run against a random hand. **Boards behind the percentages: 41,095,296 counted in all** | Hand | Boards won, about | Boards tied, about | Boards lost, about | | --- | --- | --- | --- | | A9s | 19,422,000 | 196,000 | 21,477,000 | | 55 | 21,477,000 | 196,000 | 19,422,000 | Exact total: 24 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. **A9s against 55 read as odds** | Hand | Equity as odds (to 1) | Wins one deal in | Loses one deal in | Pot odds needed to call (to 1) | | --- | --- | --- | --- | --- | | A9s | 0.905 | 2.116 | 1.913 | 1.105 | | 55 | 1.105 | 1.913 | 2.116 | 0.905 | The final column gives the least the pot must offer for each unit called for a call to break even at this equity. ## Who is ahead on which flops Across the five flop textures 55's equity moves by 10.06 points, from 51.09% on two-tone flops to 61.15% on low rainbow flops (nine high or lower). 55 stays ahead on all five textures. **A9s against 55 by flop texture, in percent** | Flop | Share of flops | A9s wins | Ties | 55 wins | A9s equity | | --- | --- | --- | --- | --- | --- | | Rainbow, ten or higher | 25.220 | 48.189 | 0.247 | 51.564 | 48.313 | | Rainbow, nine or lower | 5.689 | 38.485 | 0.722 | 60.793 | 38.846 | | Two-tone | 46.545 | 48.754 | 0.310 | 50.936 | 48.909 | | Monotone | 5.212 | 46.876 | 2.602 | 50.522 | 48.177 | | Paired | 17.334 | 44.903 | 0.536 | 54.561 | 45.171 | Flop types: rainbow means three different suits, two-tone means one suit twice, monotone means one suit three times, paired means a repeated rank. ## Compared with a random hand Compared with a random opponent, this matchup shifts A9s from 62.78% by -15.28 points and 55 from 60.33% by -7.83 points. **A9s and 55 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 | | --- | --- | --- | --- | --- | | A9s, all flops | 47.500 | 62.781 | -15.281 | 0.75660 | | A9s, rainbow, ten or higher | 48.313 | 62.781 | -14.468 | 0.76955 | | A9s, rainbow, nine or lower | 38.846 | 62.781 | -23.935 | 0.61875 | | A9s, two-tone | 48.909 | 62.781 | -13.872 | 0.77904 | | A9s, monotone | 48.177 | 62.781 | -14.604 | 0.76738 | | A9s, paired | 45.171 | 62.781 | -17.610 | 0.71950 | | 55, all flops | 52.500 | 60.325 | -7.825 | 0.87029 | | 55, rainbow, ten or higher | 51.687 | 60.325 | -8.638 | 0.85681 | | 55, rainbow, nine or lower | 61.154 | 60.325 | +0.829 | 1.01374 | | 55, two-tone | 51.091 | 60.325 | -9.234 | 0.84693 | | 55, monotone | 51.823 | 60.325 | -8.502 | 0.85906 | | 55, paired | 54.829 | 60.325 | -5.496 | 0.90889 | ## Does a shared suit matter? The suit split reads 52.69% for 55 with a shared suit and 52.31% without one. 55 does better with a shared suit, by 0.38 points. **A9s against 55 by suit overlap, in percent** | Deals | Specific deals | Share of deals | A9s wins | Ties | 55 wins | A9s equity | | --- | --- | --- | --- | --- | --- | --- | | Share a suit | 12 | 50.00 | 47.055 | 0.517 | 52.428 | 47.314 | | No shared suit | 12 | 50.00 | 47.468 | 0.436 | 52.096 | 47.686 | ## How often this matchup comes up Counting specific cards, A9s against 55 appears in 24 of the 1,624,350 ordered heads-up deals (0.0015%), and in 48 when the seats are swapped too (0.0030%). ## A worked example Worked example: both players commit $100, so $200 sits in the middle. Over every board, 55's average share is $105.00 (a gain of $5.00) and A9s' is $95.00 (a loss of $5.00). Per 1,000 deals: 55 wins about 523, A9s wins about 472, and about 5 end in a split pot. ## The same matchup from the other side Swap the hands and you get 55 with 52.50% against A9s with 47.50%. We keep one page per matchup, with the better-ranked hand first. ## Keep exploring Try As9s against 5h5d 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 As9s against 5h5d in the equity calculator](https://georgelipoker.com/tools/equity-calculator.md#p1=As9s&p2=5h5d) - [A9s combos](https://georgelipoker.com/combos/a9s.md) - [55 combos](https://georgelipoker.com/combos/55.md) - [A9s vs QJs](https://georgelipoker.com/equity/a9s-vs-qjs.md) - [A9s vs K9s](https://georgelipoker.com/equity/a9s-vs-k9s.md) - [ATo vs 55](https://georgelipoker.com/equity/ato-vs-55.md) - [All hand matchups](https://georgelipoker.com/equity.md) ## How this was computed Nothing here is simulated. The 24 deals of A9s against 55 fall into a few suit patterns, each dealt against all 1,712,304 boards, with both best five-card hands compared on every board. Ties give each hand half a win, and the flop rows count a board under each of its ten flops. Source: our own exact count from the GeorgeLiPoker poker math library. No outside data is used. ## Related - [A9s vs QJs: preflop equity](https://georgelipoker.com/equity/a9s-vs-qjs.md) - [A9s vs K9s: preflop equity](https://georgelipoker.com/equity/a9s-vs-k9s.md) - [ATo vs 55: preflop equity](https://georgelipoker.com/equity/ato-vs-55.md)