AJ vs A4s: Odds & Interactive Calculator
| Hand | Win | Tie | Equity |
|---|---|---|---|
| AJ (Ace-Jack) | 64.1% | 7.5% | 67.8% |
| A4s (Ace-Four Suited) | 28.4% | 7.5% | 32.2% |
Suited vs offsuit: AJ
| Matchup | Win | Tie | Equity |
|---|---|---|---|
| AJs | 65.2% | 7.3% | 68.9% |
| AJo | 63.7% | 7.6% | 67.5% |
How AJ vs A4s unfolds by street
Ace-Jack (AJ) is still ahead on 81% of flops against A4s, and the lead survives to the turn on 77%. A4s takes the lead on the other 19% of flops. These figures come from full board enumeration, not a simulation.
| Street | AJ still ahead | A4s flipped the lead |
|---|---|---|
| Flop | 81% | 19% |
| Turn | 77% | 23% |
AJ vs A4s is textbook domination: the hands share a card, so A4s is fighting for barely three outs. AJ wins 64.1%, A4s wins 28.4%, and 7.5% of boards chop. Note the chunky 7.5% chop rate — it surfaces whenever the shared rank plays and the kickers don't. Spots like this are where stacks quietly disappear: the dominated hand can't fold pre and can't outrun the kicker post.
Here's the intuition behind 67.8% to 32.2%: AJ wins roughly 2 of every 3 times the chips go in, but the underdog cashing 32.2% of the time is exactly why you can't slow-play and let it draw for free.
Domination is where preflop hand-reading pays off. With AJ you want stacks in; with A4s you want out, because three outs and a prayer is not a stack-off — recognizing that you're crushed against a strong range is worth more than any postflop move.
AJ vs A4s FAQ
Who wins AJ vs A4s preflop?
AJ (Ace-Jack) is the favorite, winning 64.1% of all runouts, while A4s (Ace-Four Suited) wins 28.4%. The remaining 7.5% are split pots. Counting splits as half, AJ's preflop equity is 67.8%.
Does the AJ vs A4s probability change all-in preflop?
No. Once both hands are all-in preflop the odds are set by the cards alone — position, stack size and who bet first change nothing. The only thing that moves the number is suits: AJ's equity runs from 67.1% to 68.9% depending on suitedness and which suits the two hands share, which is why different sites quote slightly different figures. It does change once board cards are dealt (AJ leads on 81% of flops) and in multiway pots, where every extra caller takes equity from both hands.
Why is A4s so bad against AJ?
Because they share a card, A4s is drawing to roughly three outs and chops 7.5% of the time — it wins only about 1 in 4. That's the danger of a dominated hand: too strong to fold, too far behind to outdraw, which is how kicker problems quietly cost full stacks.
Does AJ hold up against A4s after the flop?
AJ is still ahead on 81% of flops and stays ahead through the turn on 77% of boards; A4s takes the lead on the other 19% of flops. These are exact figures from full board enumeration.
Run any matchup in the free equity calculator · AK VS A2S · AK VS A3S · AK VS A4S · AK VS A5S · AK VS A6S · AK VS A7S
AJ against a range
All-in against one known hand is the textbook case; at the table AJ is usually up against a range. Exact equities, computed over every combo with card removal applied:
- AJ vs calling station — 61.1% against 670 combos (50.5% of hands)
- AJ vs BTN open — 60.2% against 586 combos (44.2% of hands)
- AJ vs CO open — 56.6% against 366 combos (27.6% of hands)
- AJ vs 10bb shove — 56.3% against 334 combos (25.2% of hands)