--- title: "ATs vs 66: preflop equity" url: "https://georgelipoker.com/equity/ats-vs-66.md" canonical_url: "https://georgelipoker.com/equity/ats-vs-66" last_updated: "2026-10-23" type: "reference" summary: "ATs vs 66 is close to a coin flip before the flop: 48.31% to 51.69% equity, counted exactly over every board, with the split by flop type and suit." related: ["https://georgelipoker.com/equity/ats-vs-a9s.md", "https://georgelipoker.com/equity/ats-vs-ato.md", "https://georgelipoker.com/equity/aqo-vs-66.md"] --- # ATs vs 66: preflop equity ATs vs 66 is close to a coin flip before the flop: 48.31% to 51.69% equity, counted exactly over every board, with the split by flop type and suit. Dealt all in against each other, 66 takes 51.69% of the pot on average and ATs takes the other 48.31%. ## ATs against 66: the numbers **Exact preflop results for ATs against 66, in percent** | Hand | Wins | Ties | Loses | Equity | | --- | --- | --- | --- | --- | | ATs | 48.108 | 0.412 | 51.480 | 48.314 | | 66 | 51.480 | 0.412 | 48.108 | 51.686 | Here a suited hand (ATs) meets a pocket pair (66). 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 66 a little ahead. Ties are 0.41% of the outcomes here; each tied board gives both hands half the pot. Place 13 of 169 belongs to ATs and place 17 belongs to 66 in the ranking against a random hand. **Boards behind the percentages: 41,095,296 counted in all** | Hand | Boards won, about | Boards tied, about | Boards lost, about | | --- | --- | --- | --- | | ATs | 19,770,000 | 169,000 | 21,156,000 | | 66 | 21,156,000 | 169,000 | 19,770,000 | 24 specific deals times 1,712,304 boards gives the exact total. The won, tied and lost counts are approximations from the five-decimal percentages, rounded to the nearest thousand. **ATs against 66 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 | 0.935 | 2.079 | 1.943 | 1.070 | | 66 | 1.070 | 1.943 | 2.079 | 0.935 | 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 66 prefers low rainbow flops (nine high or lower), where it holds 77.76%, and likes rainbow flops topped by a ten or better least, where it holds 45.68%. ATs takes over on rainbow flops topped by a ten or better, so the favorite before the flop is the underdog on those boards. **ATs against 66 by flop texture, in percent** | Flop | Share of flops | ATs wins | Ties | 66 wins | ATs equity | | --- | --- | --- | --- | --- | --- | | Rainbow, ten or higher | 24.595 | 54.227 | 0.195 | 45.578 | 54.325 | | Rainbow, nine or lower | 6.314 | 21.944 | 0.588 | 77.468 | 22.238 | | Two-tone | 46.545 | 49.862 | 0.257 | 49.881 | 49.990 | | Monotone | 5.212 | 47.618 | 2.449 | 49.933 | 48.843 | | Paired | 17.334 | 44.391 | 0.459 | 55.150 | 44.621 | 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 Compared with a random opponent, this matchup shifts ATs from 64.60% by -16.29 points and 66 from 63.29% by -11.60 points. **ATs and 66 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 | 48.314 | 64.602 | -16.288 | 0.74787 | | ATs, rainbow, ten or higher | 54.325 | 64.602 | -10.277 | 0.84092 | | ATs, rainbow, nine or lower | 22.238 | 64.602 | -42.364 | 0.34423 | | ATs, two-tone | 49.990 | 64.602 | -14.612 | 0.77382 | | ATs, monotone | 48.843 | 64.602 | -15.759 | 0.75606 | | ATs, paired | 44.621 | 64.602 | -19.981 | 0.69071 | | 66, all flops | 51.686 | 63.285 | -11.599 | 0.81672 | | 66, rainbow, ten or higher | 45.675 | 63.285 | -17.610 | 0.72174 | | 66, rainbow, nine or lower | 77.762 | 63.285 | +14.477 | 1.22876 | | 66, two-tone | 50.010 | 63.285 | -13.275 | 0.79023 | | 66, monotone | 51.157 | 63.285 | -12.128 | 0.80836 | | 66, paired | 55.379 | 63.285 | -7.906 | 0.87507 | ## Does a shared suit matter? Split by suits, the deals give 66 51.86% when the hands overlap in a suit and 51.51% when they do not. 66 does better with a shared suit, by 0.35 points. **ATs against 66 by suit overlap, in percent** | Deals | Specific deals | Share of deals | ATs wins | Ties | 66 wins | ATs equity | | --- | --- | --- | --- | --- | --- | --- | | Share a suit | 12 | 50.00 | 47.909 | 0.454 | 51.637 | 48.136 | | No shared suit | 12 | 50.00 | 48.307 | 0.369 | 51.324 | 48.491 | ## How often this matchup comes up The class pair covers 24 combinations of specific cards in a fixed seat order, 0.0015% of 1,624,350, and 48 (0.0030%) in either order. ## A worked example Say each player puts $100 in before the flop, making a $200 pot. On average 66 takes back $103.38 of it, which is $3.38 more than it put in, and ATs takes back $96.62, $3.38 less than it put in. In 1,000 deals of exactly this matchup, expect about 515 won outright by 66, about 481 won outright by ATs and about 4 split. ## The same matchup from the other side 66 versus ATs is this same page seen from the other hand: 51.69% for 66, 48.31% for ATs. ## Keep exploring AsTs against 6h6d 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 AsTs against 6h6d in the equity calculator](https://georgelipoker.com/tools/equity-calculator.md#p1=AsTs&p2=6h6d) - [ATs combos](https://georgelipoker.com/combos/ats.md) - [66 combos](https://georgelipoker.com/combos/66.md) - [ATs vs A9s](https://georgelipoker.com/equity/ats-vs-a9s.md) - [ATs vs ATo](https://georgelipoker.com/equity/ats-vs-ato.md) - [AQo vs 66](https://georgelipoker.com/equity/aqo-vs-66.md) - [All hand matchups](https://georgelipoker.com/equity.md) ## How this was computed The figures are counted, not estimated: 1,712,304 boards for every suit pattern of the 24 specific deals, with both seven-card hands compared each time. Equity gives half a win for a tie. For the flop rows, a board is counted once under each of the ten flops inside it. Source: our own exact count from the GeorgeLiPoker poker math library. No outside data is used. ## Related - [ATs vs A9s: preflop equity](https://georgelipoker.com/equity/ats-vs-a9s.md) - [ATs vs ATo: preflop equity](https://georgelipoker.com/equity/ats-vs-ato.md) - [AQo vs 66: preflop equity](https://georgelipoker.com/equity/aqo-vs-66.md)