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99 vs 66

99
VS
66
81.2%
equity for 99 — 66 takes 18.8%

Pair over pair — the higher pair is roughly an 80/20 favourite.

99 Win
80.9%
Tie
0.7%
99 Lose
18.4%
Card combinations
36
99 vs random
72.2% · #6
66 vs random
63.3% · #17
Breakdown

Win, tie and loss for 99

Win 80.9%Lose 18.4%

When 99 and 66 get all in before the flop, 99 wins 81.2% of the time and 66 takes 18.8%. Broken down, 99 wins outright 80.9%, chops 0.7% and loses 18.4% — 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 80.5% (for example 9s 9h against 6d 6c); with both suits shared it is 82.0% (9s 9h against 6s 6h). That is a spread of 1.41 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 99 59.2%, 66 17.1%, random 23.7%. 99 gives up 22.1 points and 66 gives up 1.6, 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, 99 is worth 72.2% against a random hand (rank 6 of 169) and 66 is worth 63.3% (rank 17). The gap between them in the ranking is only 8.9 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, 99 scoops roughly 81 pots, splits about one, and loses the remaining 18. Against eight random opponents rather than this one specific hand, 99 would be down to 17.2% and 66 to 13.7%, so the shape of this particular confrontation matters far more than either hand's standing in the overall ranking.

From 66's side, 18.8% is the break-even point for calling an all-in at 4.32:1 pot odds. Put another way, the call is profitable as long as the amount you have to put in is less than 18.8% of the pot you are playing for. 99 holds the other 81.2% 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 66 really does hold exactly 66; against the wider range a player would actually get all in with, 99's 81.2% moves. Use the individual pages for 99 and 66 to see how each of them fares against all 168 other holdings before treating this single pairing as the whole picture.

By shared suits

Overlapping suits move the number

200,000 simulated showdowns per condition. The example column shows one concrete four-card layout.

ConditionExampleCombos99 EquityWinTieLose
No shared suit9s 9h vs 6d 6c680.5%80.3%0.6%19.2%
One shared suit9s 9h vs 6s 6d2481.2%80.9%0.7%18.4%
Both suits shared9s 9h vs 6s 6h682.0%81.6%0.8%17.7%
Three-way

Adding a random third hand

200,000 simulated showdowns, with the third hand dealt at random each time.

99
59.2%
vs heads-up -22.1pt
66
17.1%
vs heads-up -1.6pt
Random third hand
23.7%
Player count

At a bigger table

Random opponents9966
172.2%63.3%
253.8%43.0%
432.5%24.7%
817.2%13.7%

Related

FAQ

99 or 66 — which is ahead preflop?

99 is the favourite. 99 takes 81.2% and 66 18.8%, a margin of 62.5 points, with 0.7% of hands ending in a chop.

Do the suits change 99 vs 66?

Yes. With no shared suit it is 80.5%, and with both suits shared it is 82.0% — a swing of up to 1.41 points.

What happens three-way?

With one extra random hand in the pot the split is 99 59.2%, 66 17.1%, random 23.7%. 99 drops 22.1 points compared with heads-up.

429 words / 33 distinct figures — Method