--- title: "99 vs 66: preflop equity" url: "https://georgelipoker.com/equity/99-vs-66.md" canonical_url: "https://georgelipoker.com/equity/99-vs-66" last_updated: "2026-10-23" type: "reference" summary: "99 is a big favorite over 66 before the flop: 81.18% to 18.82% equity, counted exactly over every board, with the split by flop type and suit." related: ["https://georgelipoker.com/equity/99-vs-a9s.md", "https://georgelipoker.com/equity/99-vs-ato.md", "https://georgelipoker.com/equity/88-vs-66.md"] --- # 99 vs 66: preflop equity 99 is a big favorite over 66 before the flop: 81.18% to 18.82% equity, counted exactly over every board, with the split by flop type and suit. The exact count puts 99 at 81.18% and 66 at 18.82% when the two hands see all five board cards. ## 99 against 66: the numbers **Exact preflop results for 99 against 66, in percent** | Hand | Wins | Ties | Loses | Equity | | --- | --- | --- | --- | --- | | 99 | 80.861 | 0.644 | 18.495 | 81.183 | | 66 | 18.495 | 0.644 | 80.861 | 18.817 | Each side holds one of the pocket pairs: 99 and 66. Both hands are pairs, so the bigger pair is ahead on every board that does not pair a card below it. A gap this wide means 66 is in trouble before the flop and has few good runouts. Ties are part of the picture: 0.64% of boards end in a split pot, and each side counts that as half a win. Among the 169 starting hands, 99 is number 6 and 66 is number 17 by strength against a random hand. **Boards behind the percentages: 61,642,944 counted in all** | Hand | Boards won, about | Boards tied, about | Boards lost, about | | --- | --- | --- | --- | | 99 | 49,845,000 | 397,000 | 11,401,000 | | 66 | 11,401,000 | 397,000 | 49,845,000 | 36 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. **99 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) | | --- | --- | --- | --- | --- | | 99 | 4.314 | 1.237 | 5.407 | 0.232 | | 66 | 0.232 | 5.407 | 1.237 | 4.314 | 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 Across the five flop textures 99's equity moves by 15.78 points, from 70.35% on low rainbow flops (nine high or lower) to 86.13% on paired flops. 99 stays ahead on all five textures, but the swing between them is large, so how the flop looks matters a great deal. **99 against 66 by flop texture, in percent** | Flop | Share of flops | 99 wins | Ties | 66 wins | 99 equity | | --- | --- | --- | --- | --- | --- | | Rainbow, ten or higher | 25.844 | 82.638 | 0.372 | 16.990 | 82.824 | | Rainbow, nine or lower | 5.065 | 70.044 | 0.620 | 29.336 | 70.354 | | Two-tone | 46.363 | 79.995 | 0.402 | 19.603 | 80.196 | | Monotone | 5.152 | 74.673 | 1.857 | 23.470 | 75.602 | | Paired | 17.576 | 85.463 | 1.334 | 13.203 | 86.130 | 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 How much does the opponent matter? Compared with its random-hand 72.06%, 99 changes by +9.12 points, and 66, from 63.29%, by -44.47. **99 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 | | --- | --- | --- | --- | --- | | 99, all flops | 81.183 | 72.057 | +9.126 | 1.12665 | | 99, rainbow, ten or higher | 82.824 | 72.057 | +10.767 | 1.14942 | | 99, rainbow, nine or lower | 70.354 | 72.057 | -1.703 | 0.97637 | | 99, two-tone | 80.196 | 72.057 | +8.139 | 1.11295 | | 99, monotone | 75.602 | 72.057 | +3.545 | 1.04920 | | 99, paired | 86.130 | 72.057 | +14.073 | 1.19530 | | 66, all flops | 18.817 | 63.285 | -44.468 | 0.29734 | | 66, rainbow, ten or higher | 17.176 | 63.285 | -46.109 | 0.27141 | | 66, rainbow, nine or lower | 29.646 | 63.285 | -33.639 | 0.46845 | | 66, two-tone | 19.804 | 63.285 | -43.481 | 0.31293 | | 66, monotone | 24.398 | 63.285 | -38.887 | 0.38553 | | 66, paired | 13.870 | 63.285 | -49.415 | 0.21917 | ## Does a shared suit matter? Of the deals of this matchup, 30 share a suit (99 at 81.32%) and 6 do not (80.51%). 99 does better with a shared suit, by 0.81 points. **99 against 66 by suit overlap, in percent** | Deals | Specific deals | Share of deals | 99 wins | Ties | 66 wins | 99 equity | | --- | --- | --- | --- | --- | --- | --- | | Share a suit | 30 | 83.33 | 80.988 | 0.660 | 18.352 | 81.318 | | No shared suit | 6 | 16.67 | 80.225 | 0.567 | 19.208 | 80.508 | ## How often this matchup comes up The class pair covers 36 combinations of specific cards in a fixed seat order, 0.0022% of 1,624,350, and 72 (0.0044%) in either order. ## A worked example To see what the equity is worth, imagine $100 each in a $200 pot. 99 is worth $162.36 on average (+$62.36); 66 is worth $37.64 (-$62.36). Over a long run, 1,000 deals split into about 809 for 99, 185 for 66 and 6 tied. ## The same matchup from the other side 66 against 99 adds nothing new: it is 18.82% for 66 and 81.18% for 99, the same figures reversed. ## Keep exploring 9s9h against 6d6c 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 9s9h against 6d6c in the equity calculator](https://georgelipoker.com/tools/equity-calculator.md#p1=9s9h&p2=6d6c) - [99 combos](https://georgelipoker.com/combos/99.md) - [66 combos](https://georgelipoker.com/combos/66.md) - [99 vs A9s](https://georgelipoker.com/equity/99-vs-a9s.md) - [99 vs ATo](https://georgelipoker.com/equity/99-vs-ato.md) - [88 vs 66](https://georgelipoker.com/equity/88-vs-66.md) - [All hand matchups](https://georgelipoker.com/equity.md) ## How this was computed Each figure is a complete count over boards. Take the 36 specific deals, group them by suit pattern, deal all 1,712,304 boards against each, and compare the two seven-card hands. Equity counts a tie as half a win; the flop rows use every one of a board's ten flops. Source: our own exact count from the GeorgeLiPoker poker math library. No outside data is used. ## Related - [99 vs A9s: preflop equity](https://georgelipoker.com/equity/99-vs-a9s.md) - [99 vs ATo: preflop equity](https://georgelipoker.com/equity/99-vs-ato.md) - [88 vs 66: preflop equity](https://georgelipoker.com/equity/88-vs-66.md)