--- title: "ATo vs A8s: preflop equity" url: "https://georgelipoker.com/equity/ato-vs-a8s.md" canonical_url: "https://georgelipoker.com/equity/ato-vs-a8s" last_updated: "2026-10-23" type: "reference" summary: "ATo is a big favorite over A8s before the flop: 67.58% to 32.42% equity, counted exactly over every board, with the split by flop type and suit." related: ["https://georgelipoker.com/equity/ato-vs-kts.md", "https://georgelipoker.com/equity/ato-vs-kqo.md", "https://georgelipoker.com/equity/kjs-vs-a8s.md"] --- # ATo vs A8s: preflop equity ATo is a big favorite over A8s before the flop: 67.58% to 32.42% equity, counted exactly over every board, with the split by flop type and suit. If ATo and A8s get all the chips in before the flop, ATo owns 67.58% of the pot in the long run and A8s owns 32.42%. ## ATo against A8s: the numbers **Exact preflop results for ATo against A8s, in percent** | Hand | Wins | Ties | Loses | Equity | | --- | --- | --- | --- | --- | | ATo | 62.503 | 10.147 | 27.350 | 67.577 | | A8s | 27.350 | 10.147 | 62.503 | 32.423 | ATo and A8s are an offsuit hand and a suited hand, in that order. 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. ATo is well ahead, and A8s needs a specific kind of board to catch up. The tie share is 10.15%: on those boards the pot is chopped and neither hand wins outright. Place 19 of 169 belongs to ATo and place 21 belongs to A8s in the ranking against a random hand. **Boards behind the percentages: 61,642,944 counted in all** | Hand | Boards won, about | Boards tied, about | Boards lost, about | | --- | --- | --- | --- | | ATo | 38,529,000 | 6,255,000 | 16,859,000 | | A8s | 16,859,000 | 6,255,000 | 38,529,000 | 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. **ATo 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) | | --- | --- | --- | --- | --- | | ATo | 2.084 | 1.600 | 3.656 | 0.480 | | A8s | 0.480 | 3.656 | 1.600 | 2.084 | 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 Rainbow flops topped by a ten or better are the best for ATo (74.30%); low rainbow flops (nine high or lower) are the worst (58.97%). ATo stays ahead on all five textures, but the swing between them is large, so how the flop looks matters a great deal. **ATo against A8s by flop texture, in percent** | Flop | Share of flops | ATo wins | Ties | A8s wins | ATo equity | | --- | --- | --- | --- | --- | --- | | Rainbow, ten or higher | 23.905 | 70.030 | 8.549 | 21.421 | 74.304 | | Rainbow, nine or lower | 7.042 | 56.904 | 4.134 | 38.962 | 58.971 | | Two-tone | 46.527 | 63.529 | 7.105 | 29.366 | 67.082 | | Monotone | 5.192 | 59.403 | 7.492 | 33.105 | 63.149 | | Paired | 17.334 | 52.573 | 23.756 | 23.671 | 64.451 | 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 Each hand has a baseline against a random hand: 62.72% for ATo, 61.94% for A8s. Here the change is +4.86 and -29.52 points. **ATo 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 | | --- | --- | --- | --- | --- | | ATo, all flops | 67.577 | 62.722 | +4.855 | 1.07741 | | ATo, rainbow, ten or higher | 74.304 | 62.722 | +11.582 | 1.18466 | | ATo, rainbow, nine or lower | 58.971 | 62.722 | -3.751 | 0.94020 | | ATo, two-tone | 67.082 | 62.722 | +4.360 | 1.06951 | | ATo, monotone | 63.149 | 62.722 | +0.427 | 1.00681 | | ATo, paired | 64.451 | 62.722 | +1.729 | 1.02757 | | A8s, all flops | 32.423 | 61.944 | -29.521 | 0.52342 | | A8s, rainbow, ten or higher | 25.696 | 61.944 | -36.248 | 0.41483 | | A8s, rainbow, nine or lower | 41.029 | 61.944 | -20.915 | 0.66236 | | A8s, two-tone | 32.918 | 61.944 | -29.026 | 0.53142 | | A8s, monotone | 36.851 | 61.944 | -25.093 | 0.59491 | | A8s, paired | 35.549 | 61.944 | -26.395 | 0.57389 | ## Does a shared suit matter? Two kinds of deal exist here. In 12 of them the hands share a suit and ATo holds 68.36%. In 24 they do not, and it holds 67.18%. ATo does better with a shared suit, by 1.18 points. **ATo against A8s by suit overlap, in percent** | Deals | Specific deals | Share of deals | ATo wins | Ties | A8s wins | ATo equity | | --- | --- | --- | --- | --- | --- | --- | | Share a suit | 12 | 33.33 | 63.225 | 10.275 | 26.500 | 68.363 | | No shared suit | 24 | 66.67 | 62.142 | 10.084 | 27.774 | 67.184 | ## 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 Put $100 each into a $200 pot and deal every board once: ATo averages $135.16 back, ahead of its $100 by $35.16, while A8s averages $64.84, short of its $100 by $35.16. Over a long run, 1,000 deals split into about 625 for ATo, 274 for A8s and 101 tied. ## The same matchup from the other side A8s versus ATo is this same page seen from the other hand: 32.42% for A8s, 67.58% for ATo. ## Keep exploring The calculator link fills in AsTh against Ad8d, 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 AsTh against Ad8d in the equity calculator](https://georgelipoker.com/tools/equity-calculator.md#p1=AsTh&p2=Ad8d) - [ATo combos](https://georgelipoker.com/combos/ato.md) - [A8s combos](https://georgelipoker.com/combos/a8s.md) - [ATo vs KTs](https://georgelipoker.com/equity/ato-vs-kts.md) - [ATo vs KQo](https://georgelipoker.com/equity/ato-vs-kqo.md) - [KJs vs A8s](https://georgelipoker.com/equity/kjs-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 36 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 - [ATo vs KTs: preflop equity](https://georgelipoker.com/equity/ato-vs-kts.md) - [ATo vs KQo: preflop equity](https://georgelipoker.com/equity/ato-vs-kqo.md) - [KJs vs A8s: preflop equity](https://georgelipoker.com/equity/kjs-vs-a8s.md)