--- title: "A8s vs A9o: preflop equity" url: "https://georgelipoker.com/equity/a8s-vs-a9o.md" canonical_url: "https://georgelipoker.com/equity/a8s-vs-a9o" last_updated: "2026-10-23" type: "reference" summary: "A9o is a big favorite over A8s before the flop: 65.25% to 34.75% equity, counted exactly over every board, with the split by flop type and suit." related: ["https://georgelipoker.com/equity/a8s-vs-kjo.md", "https://georgelipoker.com/equity/a8s-vs-55.md", "https://georgelipoker.com/equity/kts-vs-a9o.md"] --- # A8s vs A9o: preflop equity A9o is a big favorite over A8s before the flop: 65.25% to 34.75% equity, counted exactly over every board, with the split by flop type and suit. Dealt all in against each other, A9o takes 65.25% of the pot on average and A8s takes the other 34.75%. ## A8s against A9o: the numbers **Exact preflop results for A8s against A9o, in percent** | Hand | Wins | Ties | Loses | Equity | | --- | --- | --- | --- | --- | | A8s | 27.297 | 14.908 | 57.795 | 34.751 | | A9o | 57.795 | 14.908 | 27.297 | 65.249 | The matchup pits a suited hand against an offsuit hand. Because the hands share one rank, the one with the higher kicker is ahead when that rank pairs and the other hand is mostly drawing. A9o is the clear favorite, though A8s gets there on roughly one board in 3. About 14.91% of boards chop the pot, which is why equity sits slightly above the win figure for both hands. By strength against a random hand, A8s holds place 21 of 169 and A9o holds place 25. **Boards behind the percentages: 61,642,944 counted in all** | Hand | Boards won, about | Boards tied, about | Boards lost, about | | --- | --- | --- | --- | | A8s | 16,827,000 | 9,190,000 | 35,627,000 | | A9o | 35,627,000 | 9,190,000 | 16,827,000 | Exact total: 36 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. **A8s against A9o read as odds** | Hand | Equity as odds (to 1) | Wins one deal in | Loses one deal in | Pot odds needed to call (to 1) | | --- | --- | --- | --- | --- | | A8s | 0.533 | 3.663 | 1.730 | 1.878 | | A9o | 1.878 | 1.730 | 3.663 | 0.533 | The last column is the smallest pot odds, written as a pot-to-call ratio, at which a call breaks even with this equity. ## Who is ahead on which flops Across the five flop textures A9o's equity moves by 8.34 points, from 60.76% on paired flops to 69.10% on rainbow flops topped by a ten or better. A9o stays ahead on all five textures. **A8s against A9o by flop texture, in percent** | Flop | Share of flops | A8s wins | Ties | A9o wins | A8s equity | | --- | --- | --- | --- | --- | --- | | Rainbow, ten or higher | 24.588 | 23.815 | 14.177 | 62.008 | 30.903 | | Rainbow, nine or lower | 6.360 | 31.278 | 3.594 | 65.128 | 33.075 | | Two-tone | 46.527 | 29.314 | 11.247 | 59.439 | 34.937 | | Monotone | 5.192 | 33.091 | 10.566 | 56.343 | 38.374 | | Paired | 17.333 | 23.629 | 31.223 | 45.148 | 39.240 | A rainbow flop shows three suits, a two-tone flop repeats one suit, a monotone flop is a single suit, and a paired flop repeats a rank. ## Compared with a random hand Against one random hand instead, A8s holds 61.94% and A9o holds 60.77%. Facing each other changes that by -27.19 points for A8s and +4.48 points for A9o. **A8s and A9o 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 | | --- | --- | --- | --- | --- | | A8s, all flops | 34.751 | 61.944 | -27.193 | 0.56101 | | A8s, rainbow, ten or higher | 30.903 | 61.944 | -31.041 | 0.49889 | | A8s, rainbow, nine or lower | 33.075 | 61.944 | -28.869 | 0.53395 | | A8s, two-tone | 34.937 | 61.944 | -27.007 | 0.56401 | | A8s, monotone | 38.374 | 61.944 | -23.570 | 0.61950 | | A8s, paired | 39.240 | 61.944 | -22.704 | 0.63348 | | A9o, all flops | 65.249 | 60.773 | +4.476 | 1.07365 | | A9o, rainbow, ten or higher | 69.097 | 60.773 | +8.324 | 1.13697 | | A9o, rainbow, nine or lower | 66.925 | 60.773 | +6.152 | 1.10123 | | A9o, two-tone | 65.063 | 60.773 | +4.290 | 1.07059 | | A9o, monotone | 61.626 | 60.773 | +0.853 | 1.01404 | | A9o, paired | 60.760 | 60.773 | -0.013 | 0.99979 | ## Does a shared suit matter? Does suit overlap move the numbers? A9o has 66.01% when the hands share a suit and 64.87% when they do not. A9o does better with a shared suit, by 1.14 points. **A8s against A9o by suit overlap, in percent** | Deals | Specific deals | Share of deals | A8s wins | Ties | A9o wins | A8s equity | | --- | --- | --- | --- | --- | --- | --- | | Share a suit | 12 | 33.33 | 26.461 | 15.063 | 58.476 | 33.992 | | No shared suit | 24 | 66.67 | 27.716 | 14.830 | 57.454 | 35.131 | ## How often this matchup comes up Counting specific cards, A8s against A9o appears in 36 of the 1,624,350 ordered heads-up deals (0.0022%), and in 72 when the seats are swapped too (0.0044%). ## A worked example Try it with money: two players each put in $100 and the whole board runs out every possible way. A9o averages $130.50 from the $200, up $30.50; A8s averages $69.50, down $30.50. Per 1,000 deals: A9o wins about 578, A8s wins about 273, and about 149 end in a split pot. ## The same matchup from the other side A9o against A8s adds nothing new: it is 65.25% for A9o and 34.75% for A8s, the same figures reversed. ## Keep exploring Open the calculator with As8s against Ah9d already entered, a deal with no shared suit, and change any card to try your own hand. The matchups after it each swap one hand for a nearby one in the ranking. - [Open As8s against Ah9d in the equity calculator](https://georgelipoker.com/tools/equity-calculator.md#p1=As8s&p2=Ah9d) - [A8s combos](https://georgelipoker.com/combos/a8s.md) - [A9o combos](https://georgelipoker.com/combos/a9o.md) - [A8s vs KJo](https://georgelipoker.com/equity/a8s-vs-kjo.md) - [A8s vs 55](https://georgelipoker.com/equity/a8s-vs-55.md) - [KTs vs A9o](https://georgelipoker.com/equity/kts-vs-a9o.md) - [All hand matchups](https://georgelipoker.com/equity.md) ## How this was computed The figures are counted, not estimated: 1,712,304 boards for every suit pattern of the 36 specific deals, with both seven-card hands compared each time. Equity gives half a win for a tie. For the flop rows, a board is counted once under each of the ten flops inside it. Source: our own exact count from the GeorgeLiPoker poker math library. No outside data is used. ## Related - [A8s vs KJo: preflop equity](https://georgelipoker.com/equity/a8s-vs-kjo.md) - [A8s vs 55: preflop equity](https://georgelipoker.com/equity/a8s-vs-55.md) - [KTs vs A9o: preflop equity](https://georgelipoker.com/equity/kts-vs-a9o.md)