--- title: "ATs vs 55: preflop equity" url: "https://georgelipoker.com/equity/ats-vs-55.md" canonical_url: "https://georgelipoker.com/equity/ats-vs-55" last_updated: "2026-10-23" type: "reference" summary: "ATs vs 55 is close to a coin flip before the flop: 49.09% to 50.91% equity, counted exactly over every board, with the split by flop type and suit." related: ["https://georgelipoker.com/equity/ats-vs-qjs.md", "https://georgelipoker.com/equity/ats-vs-k9s.md", "https://georgelipoker.com/equity/aqo-vs-55.md"] --- # ATs vs 55: preflop equity ATs vs 55 is close to a coin flip before the flop: 49.09% to 50.91% equity, counted exactly over every board, with the split by flop type and suit. Over all 1,712,304 boards that can follow this deal, 55 finishes with 50.91% of the pot and ATs with 49.09%. ## ATs against 55: the numbers **Exact preflop results for ATs against 55, in percent** | Hand | Wins | Ties | Loses | Equity | | --- | --- | --- | --- | --- | | ATs | 48.858 | 0.472 | 50.670 | 49.094 | | 55 | 50.670 | 0.472 | 48.858 | 50.906 | We compare a suited hand with a pocket pair. A pair against two higher cards is the classic race: the pair is usually a small favorite or close to even, and each overcard that pairs is a way to take the lead. This is close to even money, with 55 a little ahead. 0.47% of boards are ties, so the equity of each hand is its win rate plus half of that. By strength against a random hand, ATs holds place 13 of 169 and 55 holds place 27. **Boards behind the percentages: 41,095,296 counted in all** | Hand | Boards won, about | Boards tied, about | Boards lost, about | | --- | --- | --- | --- | | ATs | 20,078,000 | 194,000 | 20,823,000 | | 55 | 20,823,000 | 194,000 | 20,078,000 | Exact total: 24 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. **ATs against 55 read as odds** | Hand | Equity as odds (to 1) | Wins one deal in | Loses one deal in | Pot odds needed to call (to 1) | | --- | --- | --- | --- | --- | | ATs | 0.964 | 2.047 | 1.974 | 1.037 | | 55 | 1.037 | 1.974 | 2.047 | 0.964 | The last column is the break-even price: the pot odds a call needs to offer, as a ratio of pot to call. ## Who is ahead on which flops 55 prefers low rainbow flops (nine high or lower), where it holds 75.62%, and likes rainbow flops topped by a ten or better least, where it holds 45.38%. On rainbow flops topped by a ten or better and two-tone flops the numbers flip and ATs is the one ahead. **ATs against 55 by flop texture, in percent** | Flop | Share of flops | ATs wins | Ties | 55 wins | ATs equity | | --- | --- | --- | --- | --- | --- | | Rainbow, ten or higher | 24.595 | 54.502 | 0.235 | 45.263 | 54.620 | | Rainbow, nine or lower | 6.314 | 24.029 | 0.694 | 75.277 | 24.376 | | Two-tone | 46.545 | 50.453 | 0.306 | 49.241 | 50.606 | | Monotone | 5.212 | 48.050 | 2.601 | 49.349 | 49.350 | | Paired | 17.334 | 45.853 | 0.532 | 53.615 | 46.119 | 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, ATs holds 64.60% and 55 holds 60.33%. Facing each other changes that by -15.51 points for ATs and -9.42 points for 55. **ATs and 55 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 | | --- | --- | --- | --- | --- | | ATs, all flops | 49.094 | 64.602 | -15.508 | 0.75995 | | ATs, rainbow, ten or higher | 54.620 | 64.602 | -9.982 | 0.84548 | | ATs, rainbow, nine or lower | 24.376 | 64.602 | -40.226 | 0.37733 | | ATs, two-tone | 50.606 | 64.602 | -13.996 | 0.78335 | | ATs, monotone | 49.350 | 64.602 | -15.252 | 0.76391 | | ATs, paired | 46.119 | 64.602 | -18.483 | 0.71389 | | 55, all flops | 50.906 | 60.325 | -9.419 | 0.84386 | | 55, rainbow, ten or higher | 45.380 | 60.325 | -14.945 | 0.75226 | | 55, rainbow, nine or lower | 75.624 | 60.325 | +15.299 | 1.25361 | | 55, two-tone | 49.394 | 60.325 | -10.931 | 0.81880 | | 55, monotone | 50.650 | 60.325 | -9.675 | 0.83962 | | 55, paired | 53.881 | 60.325 | -6.444 | 0.89318 | ## Does a shared suit matter? Split by suits, the deals give 55 51.08% when the hands overlap in a suit and 50.73% when they do not. 55 does better with a shared suit, by 0.35 points. **ATs against 55 by suit overlap, in percent** | Deals | Specific deals | Share of deals | ATs wins | Ties | 55 wins | ATs equity | | --- | --- | --- | --- | --- | --- | --- | | Share a suit | 12 | 50.00 | 48.665 | 0.513 | 50.822 | 48.921 | | No shared suit | 12 | 50.00 | 49.052 | 0.430 | 50.518 | 49.267 | ## How often this matchup comes up How often does it happen? 24 of the 1,624,350 ordered deals (0.0015%) are ATs against 55, and 48 (0.0030%) if either hand may sit in either seat. ## A worked example A $100 all-in from each player makes a $200 pot, and the exact equity says 55 gets $101.82 of it on average and ATs gets $98.18. A thousand deals look like this: 55 takes 507, ATs takes 488, 5 are ties. ## The same matchup from the other side 55 against ATs adds nothing new: it is 50.91% for 55 and 49.09% for ATs, the same figures reversed. ## Keep exploring Try AsTs against 5h5d 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 AsTs against 5h5d in the equity calculator](https://georgelipoker.com/tools/equity-calculator.md#p1=AsTs&p2=5h5d) - [ATs combos](https://georgelipoker.com/combos/ats.md) - [55 combos](https://georgelipoker.com/combos/55.md) - [ATs vs QJs](https://georgelipoker.com/equity/ats-vs-qjs.md) - [ATs vs K9s](https://georgelipoker.com/equity/ats-vs-k9s.md) - [AQo vs 55](https://georgelipoker.com/equity/aqo-vs-55.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 24 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 - [ATs vs QJs: preflop equity](https://georgelipoker.com/equity/ats-vs-qjs.md) - [ATs vs K9s: preflop equity](https://georgelipoker.com/equity/ats-vs-k9s.md) - [AQo vs 55: preflop equity](https://georgelipoker.com/equity/aqo-vs-55.md)