--- title: "A9o vs K9s: preflop equity" url: "https://georgelipoker.com/equity/a9o-vs-k9s.md" canonical_url: "https://georgelipoker.com/equity/a9o-vs-k9s" last_updated: "2026-10-23" type: "reference" summary: "A9o is a big favorite over K9s before the flop: 70.01% to 29.99% equity, counted exactly over every board, with the split by flop type and suit." related: ["https://georgelipoker.com/equity/a9o-vs-a5s.md", "https://georgelipoker.com/equity/a9o-vs-a6s.md", "https://georgelipoker.com/equity/kjo-vs-k9s.md"] --- # A9o vs K9s: preflop equity A9o is a big favorite over K9s before the flop: 70.01% to 29.99% equity, counted exactly over every board, with the split by flop type and suit. The exact count puts A9o at 70.01% and K9s at 29.99% when the two hands see all five board cards. ## A9o against K9s: the numbers **Exact preflop results for A9o against K9s, in percent** | Hand | Wins | Ties | Loses | Equity | | --- | --- | --- | --- | --- | | A9o | 68.988 | 2.046 | 28.966 | 70.011 | | K9s | 28.966 | 2.046 | 68.988 | 29.989 | One side is an offsuit hand, the other is a suited hand. Sharing a rank is the signature of a dominated hand, since the weaker hand is usually out-kicked when the shared rank shows up. A9o is well ahead, and K9s needs a specific kind of board to catch up. About 2.05% of boards chop the pot, which is why equity sits slightly above the win figure for both hands. Ranked by equity against a random hand, A9o is number 25 of the 169 starting hands and K9s is number 29. **Boards behind the percentages: 61,642,944 counted in all** | Hand | Boards won, about | Boards tied, about | Boards lost, about | | --- | --- | --- | --- | | A9o | 42,526,000 | 1,261,000 | 17,855,000 | | K9s | 17,855,000 | 1,261,000 | 42,526,000 | 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 K9s 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 | 2.335 | 1.450 | 3.452 | 0.428 | | K9s | 0.428 | 3.452 | 1.450 | 2.335 | 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 A9o prefers low rainbow flops (nine high or lower), where it holds 82.99%, and likes monotone flops least, where it holds 65.16%. 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 K9s by flop texture, in percent** | Flop | Share of flops | A9o wins | Ties | K9s wins | A9o equity | | --- | --- | --- | --- | --- | --- | | Rainbow, ten or higher | 24.634 | 68.073 | 1.508 | 30.419 | 68.827 | | Rainbow, nine or lower | 6.314 | 80.959 | 4.059 | 14.982 | 82.988 | | Two-tone | 46.527 | 67.197 | 1.838 | 30.965 | 68.116 | | Monotone | 5.192 | 63.555 | 3.211 | 33.234 | 65.160 | | Paired | 17.333 | 72.363 | 2.287 | 25.350 | 73.507 | 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 Start from the random-hand figures, 60.77% for A9o and 59.99% for K9s. This opponent changes them by +9.24 and -30.00 points. **A9o and K9s 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 | 70.011 | 60.773 | +9.238 | 1.15201 | | A9o, rainbow, ten or higher | 68.827 | 60.773 | +8.054 | 1.13253 | | A9o, rainbow, nine or lower | 82.988 | 60.773 | +22.215 | 1.36554 | | A9o, two-tone | 68.116 | 60.773 | +7.343 | 1.12083 | | A9o, monotone | 65.160 | 60.773 | +4.387 | 1.07219 | | A9o, paired | 73.507 | 60.773 | +12.734 | 1.20953 | | K9s, all flops | 29.989 | 59.988 | -29.999 | 0.49992 | | K9s, rainbow, ten or higher | 31.173 | 59.988 | -28.815 | 0.51965 | | K9s, rainbow, nine or lower | 17.012 | 59.988 | -42.976 | 0.28359 | | K9s, two-tone | 31.884 | 59.988 | -28.104 | 0.53151 | | K9s, monotone | 34.840 | 59.988 | -25.148 | 0.58078 | | K9s, paired | 26.493 | 59.988 | -33.495 | 0.44164 | ## Does a shared suit matter? Suit overlap shows up in the numbers. With a suit in common A9o has 71.13% equity, and with none in common it has 69.45%. A9o does better with a shared suit, by 1.68 points. **A9o against K9s by suit overlap, in percent** | Deals | Specific deals | Share of deals | A9o wins | Ties | K9s wins | A9o equity | | --- | --- | --- | --- | --- | --- | --- | | Share a suit | 12 | 33.33 | 70.074 | 2.120 | 27.806 | 71.134 | | No shared suit | 24 | 66.67 | 68.446 | 2.009 | 29.545 | 69.450 | ## How often this matchup comes up Counting specific cards, A9o against K9s 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 Put $100 each into a $200 pot and deal every board once: A9o averages $140.02 back, ahead of its $100 by $40.02, while K9s averages $59.98, short of its $100 by $40.02. In 1,000 deals of exactly this matchup, expect about 690 won outright by A9o, about 290 won outright by K9s and about 20 split. ## The same matchup from the other side K9s against A9o adds nothing new: it is 29.99% for K9s and 70.01% for A9o, the same figures reversed. ## Keep exploring As9h against Kd9d is a ready-made deal for the calculator, with no suit in common between the hands. The neighboring matchups below replace one hand with another of similar strength. - [Open As9h against Kd9d in the equity calculator](https://georgelipoker.com/tools/equity-calculator.md#p1=As9h&p2=Kd9d) - [A9o combos](https://georgelipoker.com/combos/a9o.md) - [K9s combos](https://georgelipoker.com/combos/k9s.md) - [A9o vs A5s](https://georgelipoker.com/equity/a9o-vs-a5s.md) - [A9o vs A6s](https://georgelipoker.com/equity/a9o-vs-a6s.md) - [KJo vs K9s](https://georgelipoker.com/equity/kjo-vs-k9s.md) - [All hand matchups](https://georgelipoker.com/equity.md) ## How this was computed We counted every case. Each suit pattern of the 36 specific A9o against K9s 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 - [A9o vs A5s: preflop equity](https://georgelipoker.com/equity/a9o-vs-a5s.md) - [A9o vs A6s: preflop equity](https://georgelipoker.com/equity/a9o-vs-a6s.md) - [KJo vs K9s: preflop equity](https://georgelipoker.com/equity/kjo-vs-k9s.md)