// matchups · pair vs pair

AA vs JJ pocket aces against pocket jacks

All-in before the flop, pocket aces wins 80.9% of boards, pocket jacks wins 18.6%, and 0.4% split the pot. AA is a 4.30 to 1 favourite. These are not samples: the engine dealt every one of the 1,712,304 possible five-card boards for each of the 3 ways the suits can line up, and the working is below.

AA81.15%equity · wins 80.94%
JJ18.85%equity · wins 18.65%

Equity counts a split pot as half a win for each side, which is why the two equities add to 100% and the two win rates do not.

Pair against pair

The smaller pair is drawing almost entirely to the two cards that make it a set. How far apart the ranks are barely matters. The small differences between these come from straights: which ones each pair can use, and which ones the other pair blocks.

Suits change it by 1.35 points

There are 36 ways to deal AA against JJ without the two hands sharing a card, and they fall into 3 patterns once you ignore which suit is which. Best case for AA is 81.82% (for example A♣A♦ against J♣J♦), worst is 80.47% (A♣A♦ against J♥J♠). The headline number is the average over all 36, weighted by how many deals share each pattern.

Example dealSuits in commonDeals like itAA winsSplitJJ winsAA equity
A♣A♦ vs J♣J♦A–J, A–J6 of 361,396,8728,336307,09681.82%
A♣A♦ vs J♣J♥A–J24 of 361,386,0246,955319,32581.15%
A♣A♦ vs J♥J♠none6 of 361,375,1765,574331,55480.47%

Click any deal to run it in the equity calculator, which counts the same boards in your browser, or add a third hand, a flop or a dead card to it.

How each hand wins

The made hand the winner shows down with, as a share of all boards. AA wins most often with two pair (32.7% of boards); JJ with three of a kind (9.2%). Splits happen when both hands play the same five cards or make the same hand, mostly straights.

Made handAA wins with itJJ wins with itSplit with it
Pair24.66%0.00%–
Two pair32.72%0.00%–
Three of a kind11.59%9.18%–
Straight0.69%1.63%0.33%
Flush1.72%0.98%0.07%
Full house8.66%5.95%–
Four of a kind0.91%0.88%0.00%
Straight flush0.01%0.02%0.00%
Total80.94%18.65%0.41%

When calling with JJ is right

If you call an all-in of S with JJ and know you are up against exactly AA, you win 18.85% of a pot that holds 2S plus whatever dead money D was already in the middle (blinds, antes, earlier bets). Calling breaks even when 18.85% × (2S + D) = S, so D ÷ S = 1 ÷ 0.1885 − 2 = 3.305. A 10 bb shove needs at least 33.0 bb of dead money before calling it with JJ stops losing chips. Nobody shows you their hand, though: against a real shove you are calling a range, and the push/fold charts already account for it.

Open this as a spot: JJ (dealt as J♣J♥, the most common suit pattern) facing a 10 bb all-in with 2.5 bb already in the middle, against a range of exactly AA. The calculator samples runouts rather than dealing all of them, so expect its equity to land within a few tenths of a point of the exact figure for that deal. Change the pot, the bet or the range and it reprices.

Each hand has its own page with its equity against all 169 starting hands and its push/fold range at every stack depth.

More with AA or JJ

Other matchups with AA or JJ
MatchupFirst handSplitSecond handEquity bar
AKo vs JJ43.1%0.4%56.9%
AKs vs JJ46.0%0.4%54.0%
AQo vs JJ43.1%0.4%56.9%
AQs vs JJ45.9%0.4%54.1%
KQo vs JJ43.5%0.4%56.5%
AA vs KK81.9%0.5%18.1%
AA vs QQ81.5%0.4%18.5%
KK vs JJ81.5%0.4%18.5%

Other pair vs pair matchups

Other pair vs pair matchups
MatchupFirst handSplitSecond handEquity bar
KK vs QQ81.9%0.5%18.1%
QQ vs JJ82.0%0.4%18.0%
JJ vs TT82.0%0.4%18.0%
TT vs 9982.0%0.5%18.0%
88 vs 7781.8%0.9%18.2%
AA vs 2282.2%0.5%17.8%
// how these numbers were computed
  • Exhaustive, not sampled. With four cards dealt, 48 remain, and there are C(48, 5) = 1,712,304 five-card boards. For each suit pattern our Rust engine (the same WebAssembly file the trainer runs) evaluated both seven-card hands on every board and counted wins, splits and losses. The board counts in the suit table are exact; anyone with an enumerator can reproduce them digit for digit.
  • Suit patterns. Two deals are the same pattern when one becomes the other by renaming suits (clubs to hearts, say), which cannot change who wins. Each pattern is enumerated once and weighted by how many of the 36 deals it stands for.
  • Cross-check. The site's independent Monte Carlo matrix (200,000 random boards per matchup, used on the starting-hand pages) has AA at 80.98% here, 0.17 points from the exact figure. The build fails if any matchup disagrees by more than 0.4 points.
  • All-in preflop only. This is the equity when the money goes in before the flop and five cards are dealt with no more decisions. It says nothing about how the hands play when there is betting left.
  • Raw data: aa-vs-jj.json and the summary matchups.json, built by tools/build-matchups.mjs.