--- title: "AA vs A9o: preflop equity" url: "https://georgelipoker.com/equity/aa-vs-a9o.md" canonical_url: "https://georgelipoker.com/equity/aa-vs-a9o" last_updated: "2026-10-23" type: "reference" summary: "AA is a big favorite over A9o before the flop: 93.78% to 6.22% equity, counted exactly over every board, with the split by flop type and suit." related: ["https://georgelipoker.com/equity/aa-vs-kjo.md", "https://georgelipoker.com/equity/aa-vs-55.md", "https://georgelipoker.com/equity/kk-vs-a9o.md"] --- # AA vs A9o: preflop equity AA is a big favorite over A9o before the flop: 93.78% to 6.22% equity, counted exactly over every board, with the split by flop type and suit. Dealt all in against each other, AA takes 93.78% of the pot on average and A9o takes the other 6.22%. ## AA against A9o: the numbers **Exact preflop results for AA against A9o, in percent** | Hand | Wins | Ties | Loses | Equity | | --- | --- | --- | --- | --- | | AA | 93.088 | 1.388 | 5.524 | 93.782 | | A9o | 5.524 | 1.388 | 93.088 | 6.218 | The matchup pits a pocket pair against an offsuit hand. The non-pair hand shares a rank with the pair, so two of its outs for pairing are blocked by the pair itself. This is one of the lopsided matchups: A9o wins only 5.52% of the boards outright. The tie share is 1.39%: on those boards the pot is chopped and neither hand wins outright. Among the 169 starting hands, AA is number 1 and A9o is number 25 by strength against a random hand. **Boards behind the percentages: 61,642,944 counted in all** | Hand | Boards won, about | Boards tied, about | Boards lost, about | | --- | --- | --- | --- | | AA | 57,382,000 | 856,000 | 3,405,000 | | A9o | 3,405,000 | 856,000 | 57,382,000 | The total is exact: 36 specific deals times 1,712,304 boards. The three counts are approximate, worked out from the percentages to five decimals and rounded to the nearest thousand. **AA 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) | | --- | --- | --- | --- | --- | | AA | 15.082 | 1.074 | 18.103 | 0.066 | | A9o | 0.066 | 18.103 | 1.074 | 15.082 | 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 Rainbow flops topped by a ten or better are the best for AA (95.85%); monotone flops are the worst (84.28%). AA stays ahead on all five textures. **AA against A9o by flop texture, in percent** | Flop | Share of flops | AA wins | Ties | A9o wins | AA equity | | --- | --- | --- | --- | --- | --- | | Rainbow, ten or higher | 23.782 | 95.216 | 1.271 | 3.513 | 95.851 | | Rainbow, nine or lower | 7.042 | 91.852 | 2.747 | 5.401 | 93.225 | | Two-tone | 46.215 | 93.149 | 1.531 | 5.320 | 93.915 | | Monotone | 5.130 | 83.261 | 2.036 | 14.703 | 84.279 | | Paired | 17.831 | 93.405 | 0.452 | 6.143 | 93.631 | 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 The table below sets each hand against its own random-hand baseline: a change of +8.58 points for AA, from 85.20%, and -54.55 for A9o, from 60.77%. **AA 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 | | --- | --- | --- | --- | --- | | AA, all flops | 93.782 | 85.204 | +8.578 | 1.10068 | | AA, rainbow, ten or higher | 95.851 | 85.204 | +10.647 | 1.12496 | | AA, rainbow, nine or lower | 93.225 | 85.204 | +8.021 | 1.09414 | | AA, two-tone | 93.915 | 85.204 | +8.711 | 1.10224 | | AA, monotone | 84.279 | 85.204 | -0.925 | 0.98914 | | AA, paired | 93.631 | 85.204 | +8.427 | 1.09890 | | A9o, all flops | 6.218 | 60.773 | -54.555 | 0.10232 | | A9o, rainbow, ten or higher | 4.149 | 60.773 | -56.624 | 0.06827 | | A9o, rainbow, nine or lower | 6.775 | 60.773 | -53.998 | 0.11148 | | A9o, two-tone | 6.085 | 60.773 | -54.688 | 0.10013 | | A9o, monotone | 15.721 | 60.773 | -45.052 | 0.25868 | | A9o, paired | 6.369 | 60.773 | -54.404 | 0.10480 | ## Does a shared suit matter? Of the deals of this matchup, 24 share a suit (AA at 94.08%) and 12 do not (93.18%). AA does better with a shared suit, by 0.90 points. **AA against A9o by suit overlap, in percent** | Deals | Specific deals | Share of deals | AA wins | Ties | A9o wins | AA equity | | --- | --- | --- | --- | --- | --- | --- | | Share a suit | 24 | 66.67 | 93.371 | 1.420 | 5.209 | 94.081 | | No shared suit | 12 | 33.33 | 92.522 | 1.325 | 6.153 | 93.184 | ## How often this matchup comes up Counting specific cards, AA 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 Say each player puts $100 in before the flop, making a $200 pot. On average AA takes back $187.56 of it, which is $87.56 more than it put in, and A9o takes back $12.44, $87.56 less than it put in. Think in thousands: about 931 of 1,000 go to AA, about 55 go to A9o, and about 14 are chopped. ## The same matchup from the other side A9o versus AA is this same page seen from the other hand: 6.22% for A9o, 93.78% for AA. ## Keep exploring Try AsAh against Ad9c 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 AsAh against Ad9c in the equity calculator](https://georgelipoker.com/tools/equity-calculator.md#p1=AsAh&p2=Ad9c) - [AA combos](https://georgelipoker.com/combos/aa.md) - [A9o combos](https://georgelipoker.com/combos/a9o.md) - [AA vs KJo](https://georgelipoker.com/equity/aa-vs-kjo.md) - [AA vs 55](https://georgelipoker.com/equity/aa-vs-55.md) - [KK vs A9o](https://georgelipoker.com/equity/kk-vs-a9o.md) - [All hand matchups](https://georgelipoker.com/equity.md) ## How this was computed All 1,712,304 five-card boards are dealt for every suit pattern among the 36 specific deals of AA against A9o, and both hands are scored on each. That is a full count, so the percentages are exact. Ties are half a win each, and each board appears once per flop it contains. Source: our own exact count from the GeorgeLiPoker poker math library. No outside data is used. ## Related - [AA vs KJo: preflop equity](https://georgelipoker.com/equity/aa-vs-kjo.md) - [AA vs 55: preflop equity](https://georgelipoker.com/equity/aa-vs-55.md) - [KK vs A9o: preflop equity](https://georgelipoker.com/equity/kk-vs-a9o.md)