ATo vs A9o: preflop equity

Over all 1,712,304 boards that can follow this deal, ATo finishes with 72.03% of the pot and A9o with 27.97%.

ATo

72.03%

Wins 66.70%, ties 10.65%

A9o

27.97%

Wins 22.65%, ties 10.65%

Equity counts a tie as half a win. Exact over every board.

ATo against A9o: the numbers

Exact preflop results for ATo against A9o, in percent
HandWinsTiesLosesEquity
ATo66.70410.64922.64772.029
A9o22.64710.64966.70427.971

ATo meets A9o, and both are offsuit hands. Sharing a rank is the signature of a dominated hand, since the weaker hand is usually out-kicked when the shared rank shows up.

That is a clear edge, 72.03% to 27.97%, but A9o still wins often enough that one hand proves nothing. Ties are 10.65% of the outcomes here; each tied board gives both hands half the pot.

ATo ranks number 19 of 169 starting hands, and A9o ranks number 25, by equity against a random hand.

Boards behind the percentages: 184,928,832 counted in all
HandBoards won, aboutBoards tied, aboutBoards lost, about
ATo123,355,00019,693,00041,881,000
A9o41,881,00019,693,000123,355,000

Exact total: 108 deals times 1,712,304 boards. The other three counts come from the five-decimal percentages and are rounded to the nearest thousand, so read them as approximate.

ATo against A9o read as odds
HandEquity as odds (to 1)Wins one deal inLoses one deal inPot odds needed to call (to 1)
ATo2.5751.4994.4160.388
A9o0.3884.4161.4992.575

The last column is the smallest pot odds, written as a pot-to-call ratio, at which a call breaks even with this equity.

Who is ahead on which flops

The flop changes the picture. ATo does best on rainbow flops topped by a ten or better, at 76.91%, and worst on low rainbow flops (nine high or lower), at 62.30%. ATo stays ahead on all five textures.

ATo against A9o by flop texture, in percent
FlopShare of flopsATo winsTiesA9o winsATo equity
Rainbow, ten or higher24.00372.5508.71118.73976.906
Rainbow, nine or lower7.04260.1234.35935.51862.302
Two-tone46.47769.0887.60323.30972.890
Monotone5.14463.7407.77328.48767.627
Paired17.33455.77024.90919.32168.225

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

Compared with a random opponent, this matchup shifts ATo from 62.72% by +9.31 points and A9o from 60.77% by -32.80 points.

ATo and A9o here compared with each against a random hand, in percent
CaseEquity hereAgainst a random handChange in pointsTimes the random-hand equity
ATo, all flops72.02962.722+9.3071.14838
ATo, rainbow, ten or higher76.90662.722+14.1841.22614
ATo, rainbow, nine or lower62.30262.722-0.4200.99330
ATo, two-tone72.89062.722+10.1681.16211
ATo, monotone67.62762.722+4.9051.07820
ATo, paired68.22562.722+5.5031.08774
A9o, all flops27.97160.773-32.8020.46025
A9o, rainbow, ten or higher23.09460.773-37.6790.38000
A9o, rainbow, nine or lower37.69860.773-23.0750.62031
A9o, two-tone27.11060.773-33.6630.44609
A9o, monotone32.37360.773-28.4000.53269
A9o, paired31.77560.773-28.9980.52285

Does a shared suit matter?

When the hands share a suit, ATo holds 72.13%; when they do not, it holds 71.67%. ATo does better with a shared suit, by 0.46 points.

ATo against A9o by suit overlap, in percent
DealsSpecific dealsShare of dealsATo winsTiesA9o winsATo equity
Share a suit8477.7866.78810.68822.52472.132
No shared suit2422.2266.41210.51323.07571.668

How often this matchup comes up

Out of 1,624,350 ways to deal two seats two cards each, 108 are ATo in one seat and A9o in the other (0.0066%); with the seats swapped too, 216 (0.0133%).

A worked example

Put $100 each into a $200 pot and deal every board once: ATo averages $144.06 back, ahead of its $100 by $44.06, while A9o averages $55.94, short of its $100 by $44.06.

In 1,000 deals of exactly this matchup, expect about 667 won outright by ATo, about 226 won outright by A9o and about 107 split.

The same matchup from the other side

The reversed view, A9o against ATo, shows 27.97% for A9o and 72.03% for ATo. It is the same count, so it redirects here.

Open the calculator with AsTh against Ad9c already entered, a deal with no shared suit, and change any card to try your own hand. The matchups after it each swap one hand for a nearby one in the ranking.

How this was computed

Method: exact enumeration. The 108 specific deals are grouped by suit pattern, each is run against all 1,712,304 boards, and both seven-card hands are scored. Equity adds half of every tie, and flop textures are tallied over the ten flops inside each board.

Source: our own exact count from the GeorgeLiPoker poker math library. No outside data is used.

Bring your own hands to a session

Review the spots you actually play against these numbers in a Game Assessment, and leave with a one-page written plan.

Book a session