--- title: "A9o vs J9s: preflop equity" url: "https://georgelipoker.com/equity/a9o-vs-j9s.md" canonical_url: "https://georgelipoker.com/equity/a9o-vs-j9s" last_updated: "2026-10-23" type: "reference" summary: "A9o is a big favorite over J9s before the flop: 67.05% to 32.96% equity, counted exactly over every board, with the split by flop type and suit." related: ["https://georgelipoker.com/equity/a9o-vs-jto.md", "https://georgelipoker.com/equity/a9o-vs-t9s.md", "https://georgelipoker.com/equity/kjo-vs-j9s.md"] --- # A9o vs J9s: preflop equity A9o is a big favorite over J9s before the flop: 67.05% to 32.96% equity, counted exactly over every board, with the split by flop type and suit. The exact count puts A9o at 67.05% and J9s at 32.95% when the two hands see all five board cards. ## A9o against J9s: the numbers **Exact preflop results for A9o against J9s, in percent** | Hand | Wins | Ties | Loses | Equity | | --- | --- | --- | --- | --- | | A9o | 66.112 | 1.867 | 32.021 | 67.045 | | J9s | 32.021 | 1.867 | 66.112 | 32.955 | Here an offsuit hand (A9o) meets a suited hand (J9s). Sharing a rank is the signature of a dominated hand, since the weaker hand is usually out-kicked when the shared rank shows up. A lead of 34.10 points is large but not decisive: J9s still takes about 320 of every 1,000 deals. Of every 100 boards, about 1.87 are split pots, and the equity figures already include them. A9o ranks number 25 of 169 starting hands, and J9s ranks number 55, by equity against a random hand. **Boards behind the percentages: 61,642,944 counted in all** | Hand | Boards won, about | Boards tied, about | Boards lost, about | | --- | --- | --- | --- | | A9o | 40,753,000 | 1,151,000 | 19,739,000 | | J9s | 19,739,000 | 1,151,000 | 40,753,000 | The board total is exact, 36 deals at 1,712,304 boards each. Won, tied and lost counts are rounded to the nearest thousand from the five-decimal percentages. **A9o against J9s read as odds** | Hand | Equity as odds (to 1) | Wins one deal in | Loses one deal in | Pot odds needed to call (to 1) | | --- | --- | --- | --- | --- | | A9o | 2.034 | 1.513 | 3.123 | 0.492 | | J9s | 0.492 | 3.123 | 1.513 | 2.034 | 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 By flop texture, A9o's equity runs from 62.99% on monotone flops up to 80.40% on low rainbow flops (nine high or lower). A9o stays ahead on all five textures, but the swing between them is large, so how the flop looks matters a great deal. **A9o against J9s by flop texture, in percent** | Flop | Share of flops | A9o wins | Ties | J9s wins | A9o equity | | --- | --- | --- | --- | --- | --- | | Rainbow, ten or higher | 24.634 | 64.468 | 1.411 | 34.121 | 65.173 | | Rainbow, nine or lower | 6.314 | 78.783 | 3.234 | 17.983 | 80.400 | | Two-tone | 46.527 | 64.183 | 1.648 | 34.169 | 65.007 | | Monotone | 5.192 | 61.416 | 3.138 | 35.446 | 62.985 | | Paired | 17.333 | 70.414 | 2.226 | 27.360 | 71.527 | 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 Start from the random-hand figures, 60.77% for A9o and 55.66% for J9s. This opponent changes them by +6.28 and -22.71 points. **A9o and J9s 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 | | --- | --- | --- | --- | --- | | A9o, all flops | 67.045 | 60.773 | +6.272 | 1.10320 | | A9o, rainbow, ten or higher | 65.173 | 60.773 | +4.400 | 1.07240 | | A9o, rainbow, nine or lower | 80.400 | 60.773 | +19.627 | 1.32296 | | A9o, two-tone | 65.007 | 60.773 | +4.234 | 1.06967 | | A9o, monotone | 62.985 | 60.773 | +2.212 | 1.03640 | | A9o, paired | 71.527 | 60.773 | +10.754 | 1.17695 | | J9s, all flops | 32.955 | 55.662 | -22.707 | 0.59206 | | J9s, rainbow, ten or higher | 34.827 | 55.662 | -20.835 | 0.62569 | | J9s, rainbow, nine or lower | 19.600 | 55.662 | -36.062 | 0.35213 | | J9s, two-tone | 34.993 | 55.662 | -20.669 | 0.62867 | | J9s, monotone | 37.015 | 55.662 | -18.647 | 0.66500 | | J9s, paired | 28.473 | 55.662 | -27.189 | 0.51153 | ## Does a shared suit matter? Looking only at deals where the hands share a suit, A9o has 68.10%; looking only at deals where they do not, 66.52%. A9o does better with a shared suit, by 1.58 points. **A9o against J9s by suit overlap, in percent** | Deals | Specific deals | Share of deals | A9o wins | Ties | J9s wins | A9o equity | | --- | --- | --- | --- | --- | --- | --- | | Share a suit | 12 | 33.33 | 67.127 | 1.939 | 30.934 | 68.097 | | No shared suit | 24 | 66.67 | 65.604 | 1.831 | 32.565 | 66.519 | ## How often this matchup comes up This page stands for 36 specific-card matchups (0.0022% of 1,624,350 ordered deals), or 72 once you count the seats both ways (0.0044%). ## A worked example To see what the equity is worth, imagine $100 each in a $200 pot. A9o is worth $134.10 on average (+$34.10); J9s is worth $65.90 (-$34.10). In 1,000 deals of exactly this matchup, expect about 661 won outright by A9o, about 320 won outright by J9s and about 19 split. ## The same matchup from the other side J9s against A9o adds nothing new: it is 32.95% for J9s and 67.05% for A9o, the same figures reversed. ## Keep exploring Open the calculator with As9h against Jd9d 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 As9h against Jd9d in the equity calculator](https://georgelipoker.com/tools/equity-calculator.md#p1=As9h&p2=Jd9d) - [A9o combos](https://georgelipoker.com/combos/a9o.md) - [J9s combos](https://georgelipoker.com/combos/j9s.md) - [A9o vs JTo](https://georgelipoker.com/equity/a9o-vs-jto.md) - [A9o vs T9s](https://georgelipoker.com/equity/a9o-vs-t9s.md) - [KJo vs J9s](https://georgelipoker.com/equity/kjo-vs-j9s.md) - [All hand matchups](https://georgelipoker.com/equity.md) ## How this was computed Each figure is a complete count over boards. Take the 36 specific deals, group them by suit pattern, deal all 1,712,304 boards against each, and compare the two seven-card hands. Equity counts a tie as half a win; the flop rows use every one of a board's ten flops. Source: our own exact count from the GeorgeLiPoker poker math library. No outside data is used. ## Related - [A9o vs JTo: preflop equity](https://georgelipoker.com/equity/a9o-vs-jto.md) - [A9o vs T9s: preflop equity](https://georgelipoker.com/equity/a9o-vs-t9s.md) - [KJo vs J9s: preflop equity](https://georgelipoker.com/equity/kjo-vs-j9s.md)