66 vs 55
Pair over pair — the higher pair is roughly an 80/20 favourite.
- 66 Win
- 80.3%
- Tie
- 2.0%
- 66 Lose
- 17.8%
- Card combinations
- 36
- 66 vs random
- 63.3% · #17
- 55 vs random
- 60.3% · #27
Win, tie and loss for 66
When 66 and 55 get all in before the flop, 66 wins 81.3% of the time and 55 takes 18.7%. Broken down, 66 wins outright 80.3%, chops 2.0% and loses 17.8% — a margin of 62.5 points. Pair over pair — the higher pair is roughly an 80/20 favourite.
The same matchup shifts depending on how the suits overlap. With no shared suit the number is 80.7% (for example 6s 6h against 5d 5c); with both suits shared it is 82.0% (6s 6h against 5s 5h). That is a spread of 1.32 points across the 36 distinct card combinations, and it comes almost entirely from whether the two hands are fighting over the same flush.
Add a third player holding a random hand and the split becomes 66 51.0%, 55 16.7%, random 32.3%. 66 gives up 30.3 points and 55 gives up 2, so the favourite loses more than the underdog does. Extra players always eat into the leader's share faster than into anyone else's.
Taken on their own, 66 is worth 63.3% against a random hand (rank 17 of 169) and 55 is worth 60.3% (rank 27). The gap between them in the ranking is only 3 points, yet head to head the gap is 62.5 points — a reminder that a ranking table and a direct matchup are two different questions.
Framed as a run of one hundred identical all-ins, 66 scoops roughly 80 pots, splits about 2, and loses the remaining 18. Against eight random opponents rather than this one specific hand, 66 would be down to 13.7% and 55 to 13.2%, so the shape of this particular confrontation matters far more than either hand's standing in the overall ranking.
From 55's side, 18.7% is the break-even point for calling an all-in at 4.35:1 pot odds. Put another way, the call is profitable as long as the amount you have to put in is less than 18.7% of the pot you are playing for. 66 holds the other 81.3% of that same pot.
Two caveats keep this figure honest. First, it is showdown equity across all 36 card combinations with five board cards still to come — there is no fold equity in it, so the value of shoving in practice is usually higher than the raw percentage suggests. Second, it assumes 55 really does hold exactly 55; against the wider range a player would actually get all in with, 66's 81.3% moves. Use the individual pages for 66 and 55 to see how each of them fares against all 168 other holdings before treating this single pairing as the whole picture.
Overlapping suits move the number
200,000 simulated showdowns per condition. The example column shows one concrete four-card layout.
| Condition | Example | Combos | 66 Equity | Win | Tie | Lose |
|---|---|---|---|---|---|---|
| No shared suit | 6s 6h vs 5d 5c | 6 | 80.7% | 79.8% | 1.9% | 18.3% |
| One shared suit | 6s 6h vs 5s 5d | 24 | 81.2% | 80.2% | 2.0% | 17.8% |
| Both suits shared | 6s 6h vs 5s 5h | 6 | 82.0% | 81.0% | 2.0% | 16.9% |
Adding a random third hand
200,000 simulated showdowns, with the third hand dealt at random each time.
At a bigger table
| Random opponents | 66 | 55 |
|---|---|---|
| 1 | 63.3% | 60.3% |
| 2 | 43.0% | 40.1% |
| 4 | 24.7% | 22.6% |
| 8 | 13.7% | 13.2% |
Related
FAQ
66 or 55 — which is ahead preflop?
66 is the favourite. 66 takes 81.3% and 55 18.7%, a margin of 62.5 points, with 2.0% of hands ending in a chop.
Do the suits change 66 vs 55?
Yes. With no shared suit it is 80.7%, and with both suits shared it is 82.0% — a swing of up to 1.32 points.
What happens three-way?
With one extra random hand in the pot the split is 66 51.0%, 55 16.7%, random 32.3%. 66 drops 30.3 points compared with heads-up.
429 words / 33 distinct figures — Method