--- title: "66 vs A5s: preflop equity" url: "https://georgelipoker.com/equity/66-vs-a5s.md" canonical_url: "https://georgelipoker.com/equity/66-vs-a5s" last_updated: "2026-10-23" type: "reference" summary: "66 is a big favorite over A5s before the flop: 65.62% to 34.38% equity, counted exactly over every board, with the split by flop type and suit." related: ["https://georgelipoker.com/equity/66-vs-a6s.md", "https://georgelipoker.com/equity/66-vs-kto.md", "https://georgelipoker.com/equity/a9s-vs-a5s.md"] --- # 66 vs A5s: preflop equity 66 is a big favorite over A5s before the flop: 65.62% to 34.38% equity, counted exactly over every board, with the split by flop type and suit. Before any board card is dealt, 66 holds 65.62% equity against A5s, which leaves A5s with 34.38%. ## 66 against A5s: the numbers **Exact preflop results for 66 against A5s, in percent** | Hand | Wins | Ties | Loses | Equity | | --- | --- | --- | --- | --- | | 66 | 65.391 | 0.464 | 34.145 | 65.623 | | A5s | 34.145 | 0.464 | 65.391 | 34.377 | We compare a pocket pair with a suited hand. The pair sits between the other hand's two cards: one is higher and one is lower, so the pair is exposed to the higher card. 66 is the clear favorite, though A5s gets there on roughly one board in 3. Of every 100 boards, about 0.46 are split pots, and the equity figures already include them. In the ranking of all 169 starting hands, 66 is number 17 and A5s is number 30. **Boards behind the percentages: 41,095,296 counted in all** | Hand | Boards won, about | Boards tied, about | Boards lost, about | | --- | --- | --- | --- | | 66 | 26,873,000 | 191,000 | 14,032,000 | | A5s | 14,032,000 | 191,000 | 26,873,000 | The board total is exact, 24 deals at 1,712,304 boards each. Won, tied and lost counts are rounded to the nearest thousand from the five-decimal percentages. **66 against A5s read as odds** | Hand | Equity as odds (to 1) | Wins one deal in | Loses one deal in | Pot odds needed to call (to 1) | | --- | --- | --- | --- | --- | | 66 | 1.909 | 1.529 | 2.929 | 0.524 | | A5s | 0.524 | 2.929 | 1.529 | 1.909 | 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 77.57%, and likes monotone flops least, where it holds 62.15%. 66 stays ahead on all five textures, but the swing between them is large, so how the flop looks matters a great deal. **66 against A5s by flop texture, in percent** | Flop | Share of flops | 66 wins | Ties | A5s wins | 66 equity | | --- | --- | --- | --- | --- | --- | | Rainbow, ten or higher | 25.220 | 65.363 | 0.251 | 34.386 | 65.488 | | Rainbow, nine or lower | 5.689 | 77.227 | 0.689 | 22.084 | 77.571 | | Two-tone | 46.545 | 64.410 | 0.304 | 35.286 | 64.562 | | Monotone | 5.212 | 60.908 | 2.480 | 36.612 | 62.148 | | Paired | 17.334 | 65.529 | 0.520 | 33.951 | 65.789 | Flop types: rainbow means three different suits, two-tone means one suit twice, monotone means one suit three times, paired means a repeated rank. ## Compared with a random hand Start from the random-hand figures, 63.29% for 66 and 59.92% for A5s. This opponent changes them by +2.33 and -25.54 points. **66 and A5s 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 | | --- | --- | --- | --- | --- | | 66, all flops | 65.623 | 63.285 | +2.338 | 1.03694 | | 66, rainbow, ten or higher | 65.488 | 63.285 | +2.203 | 1.03481 | | 66, rainbow, nine or lower | 77.571 | 63.285 | +14.286 | 1.22574 | | 66, two-tone | 64.562 | 63.285 | +1.277 | 1.02018 | | 66, monotone | 62.148 | 63.285 | -1.137 | 0.98203 | | 66, paired | 65.789 | 63.285 | +2.504 | 1.03957 | | A5s, all flops | 34.377 | 59.923 | -25.546 | 0.57369 | | A5s, rainbow, ten or higher | 34.512 | 59.923 | -25.411 | 0.57594 | | A5s, rainbow, nine or lower | 22.429 | 59.923 | -37.494 | 0.37430 | | A5s, two-tone | 35.438 | 59.923 | -24.485 | 0.59139 | | A5s, monotone | 37.852 | 59.923 | -22.071 | 0.63168 | | A5s, paired | 34.211 | 59.923 | -25.712 | 0.57092 | ## Does a shared suit matter? The suit split reads 65.90% for 66 with a shared suit and 65.35% without one. 66 does better with a shared suit, by 0.55 points. **66 against A5s by suit overlap, in percent** | Deals | Specific deals | Share of deals | 66 wins | Ties | A5s wins | 66 equity | | --- | --- | --- | --- | --- | --- | --- | | Share a suit | 12 | 50.00 | 65.642 | 0.506 | 33.852 | 65.895 | | No shared suit | 12 | 50.00 | 65.140 | 0.421 | 34.439 | 65.350 | ## How often this matchup comes up Exactly 24 specific deals fit this matchup in one seat order, which is 0.0015% of 1,624,350; both orders together give 48, or 0.0030%. ## A worked example With $100 from each side, the $200 pot is split on average as $131.24 for 66 and $68.76 for A5s; the first side gains $31.24 per all-in and the second gives up $31.24. A thousand deals look like this: 66 takes 654, A5s takes 341, 5 are ties. ## The same matchup from the other side Swap the hands and you get A5s with 34.38% against 66 with 65.62%. We keep one page per matchup, with the better-ranked hand first. ## Keep exploring 6s6h against Ad5d 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 6s6h against Ad5d in the equity calculator](https://georgelipoker.com/tools/equity-calculator.md#p1=6s6h&p2=Ad5d) - [66 combos](https://georgelipoker.com/combos/66.md) - [A5s combos](https://georgelipoker.com/combos/a5s.md) - [66 vs A6s](https://georgelipoker.com/equity/66-vs-a6s.md) - [66 vs KTo](https://georgelipoker.com/equity/66-vs-kto.md) - [A9s vs A5s](https://georgelipoker.com/equity/a9s-vs-a5s.md) - [All hand matchups](https://georgelipoker.com/equity.md) ## How this was computed This is an exact count with no sampling. For the 24 ways to deal one 66 and one A5s without reusing a card, grouped by suit pattern, every one of the 1,712,304 possible boards is dealt and both seven-card hands are compared. A tie counts as half a win in the equity column, and each board is counted once under each of its ten three-card flops. Source: our own exact count from the GeorgeLiPoker poker math library. No outside data is used. ## Related - [66 vs A6s: preflop equity](https://georgelipoker.com/equity/66-vs-a6s.md) - [66 vs KTo: preflop equity](https://georgelipoker.com/equity/66-vs-kto.md) - [A9s vs A5s: preflop equity](https://georgelipoker.com/equity/a9s-vs-a5s.md)