--- title: "A9s vs A8s: preflop equity" url: "https://georgelipoker.com/equity/a9s-vs-a8s.md" canonical_url: "https://georgelipoker.com/equity/a9s-vs-a8s" last_updated: "2026-10-23" type: "reference" summary: "A9s is a big favorite over A8s before the flop: 66.71% to 33.30% equity, counted exactly over every board, with the split by flop type and suit." related: ["https://georgelipoker.com/equity/a9s-vs-kts.md", "https://georgelipoker.com/equity/a9s-vs-kqo.md", "https://georgelipoker.com/equity/ato-vs-a8s.md"] --- # A9s vs A8s: preflop equity A9s is a big favorite over A8s before the flop: 66.71% to 33.30% equity, counted exactly over every board, with the split by flop type and suit. Dealt all in against each other, A9s takes 66.71% of the pot on average and A8s takes the other 33.29%. ## A9s against A8s: the numbers **Exact preflop results for A9s against A8s, in percent** | Hand | Wins | Ties | Loses | Equity | | --- | --- | --- | --- | --- | | A9s | 59.657 | 14.095 | 26.248 | 66.705 | | A8s | 26.248 | 14.095 | 59.657 | 33.295 | A9s meets A8s, and both are suited hands. Sharing a rank is the signature of a dominated hand, since the weaker hand is usually out-kicked when the shared rank shows up. A9s is well ahead, and A8s needs a specific kind of board to catch up. A split pot comes up on 14.10% of boards, so the wins and the equity differ by half of that. Place 18 of 169 belongs to A9s and place 21 belongs to A8s in the ranking against a random hand. **Boards behind the percentages: 20,547,648 counted in all** | Hand | Boards won, about | Boards tied, about | Boards lost, about | | --- | --- | --- | --- | | A9s | 12,258,000 | 2,896,000 | 5,393,000 | | A8s | 5,393,000 | 2,896,000 | 12,258,000 | Exact total: 12 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 A8s 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 | 2.003 | 1.676 | 3.810 | 0.499 | | A8s | 0.499 | 3.810 | 1.676 | 2.003 | 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 By flop texture, A9s' equity runs from 61.99% on monotone flops up to 69.94% on rainbow flops topped by a ten or better. A9s stays ahead on all five textures. **A9s against A8s by flop texture, in percent** | Flop | Share of flops | A9s wins | Ties | A8s wins | A9s equity | | --- | --- | --- | --- | --- | --- | | Rainbow, ten or higher | 24.526 | 63.047 | 13.780 | 23.173 | 69.937 | | Rainbow, nine or lower | 6.383 | 66.277 | 3.445 | 30.278 | 68.000 | | Two-tone | 46.543 | 61.730 | 10.412 | 27.858 | 66.936 | | Monotone | 5.215 | 56.799 | 10.380 | 32.821 | 61.989 | | Paired | 17.333 | 47.720 | 29.469 | 22.811 | 62.454 | Rainbow flops have three suits, two-tone flops repeat one suit, monotone flops are all one suit, and paired flops repeat a rank. ## Compared with a random hand Against one random hand instead, A9s holds 62.78% and A8s holds 61.94%. Facing each other changes that by +3.93 points for A9s and -28.65 points for A8s. **A9s and A8s 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 | 66.705 | 62.781 | +3.924 | 1.06250 | | A9s, rainbow, ten or higher | 69.937 | 62.781 | +7.156 | 1.11398 | | A9s, rainbow, nine or lower | 68.000 | 62.781 | +5.219 | 1.08313 | | A9s, two-tone | 66.936 | 62.781 | +4.155 | 1.06618 | | A9s, monotone | 61.989 | 62.781 | -0.792 | 0.98738 | | A9s, paired | 62.454 | 62.781 | -0.327 | 0.99479 | | A8s, all flops | 33.295 | 61.944 | -28.649 | 0.53750 | | A8s, rainbow, ten or higher | 30.063 | 61.944 | -31.881 | 0.48533 | | A8s, rainbow, nine or lower | 32.000 | 61.944 | -29.944 | 0.51660 | | A8s, two-tone | 33.064 | 61.944 | -28.880 | 0.53377 | | A8s, monotone | 38.011 | 61.944 | -23.933 | 0.61363 | | A8s, paired | 37.546 | 61.944 | -24.398 | 0.60613 | ## Does a shared suit matter? The hands cannot hold a suit in common here, which leaves a single case and a single number: 66.71% for A9s. **A9s against A8s by suit overlap, in percent** | Deals | Specific deals | Share of deals | A9s wins | Ties | A8s wins | A9s equity | | --- | --- | --- | --- | --- | --- | --- | | Share a suit | 0 | 0.00 | not possible | not possible | not possible | not possible | | No shared suit | 12 | 100.00 | 59.657 | 14.095 | 26.248 | 66.705 | ## How often this matchup comes up Exactly 12 specific deals fit this matchup in one seat order, which is 0.0007% of 1,624,350; both orders together give 24, or 0.0015%. ## A worked example To see what the equity is worth, imagine $100 each in a $200 pot. A9s is worth $133.42 on average (+$33.42); A8s is worth $66.58 (-$33.42). Think in thousands: about 597 of 1,000 go to A9s, about 262 go to A8s, and about 141 are chopped. ## The same matchup from the other side The mirror image, A8s against A9s, is 33.29% to 66.71%, and its address redirects to this page. ## Keep exploring The calculator link fills in As9s against Ah8h, a deal where the two hands share no suit. Change any card to test your own hand. The neighboring matchups below swap one of the two hands for one of similar strength. - [Open As9s against Ah8h in the equity calculator](https://georgelipoker.com/tools/equity-calculator.md#p1=As9s&p2=Ah8h) - [A9s combos](https://georgelipoker.com/combos/a9s.md) - [A8s combos](https://georgelipoker.com/combos/a8s.md) - [A9s vs KTs](https://georgelipoker.com/equity/a9s-vs-kts.md) - [A9s vs KQo](https://georgelipoker.com/equity/a9s-vs-kqo.md) - [ATo vs A8s](https://georgelipoker.com/equity/ato-vs-a8s.md) - [All hand matchups](https://georgelipoker.com/equity.md) ## How this was computed The page is built from a full enumeration: 1,712,304 boards, every suit pattern of the 12 specific deals, both seven-card hands evaluated. A tie is worth half a win to each hand, and a board is tallied under each of its ten possible flops for the texture rows. Source: our own exact count from the GeorgeLiPoker poker math library. No outside data is used. ## Related - [A9s vs KTs: preflop equity](https://georgelipoker.com/equity/a9s-vs-kts.md) - [A9s vs KQo: preflop equity](https://georgelipoker.com/equity/a9s-vs-kqo.md) - [ATo vs A8s: preflop equity](https://georgelipoker.com/equity/ato-vs-a8s.md)