AKo vs A5s ace-king offsuit against ace-five suited
All-in before the flop, ace-king offsuit wins 66.2% of boards, ace-five suited wins 29.3%, and 4.5% split the pot. AKo is a 2.17 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 2 ways the suits can line up, and the working is below.
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.
Two hands sharing a card: domination
When both hands hold the same rank, pairing it helps both of them and the other card decides it. The dominated hand needs its lower card to pair, so it wins far less often than two unrelated cards would.
Suits change it by 1.22 points
There are 36 ways to deal AKo against A5s without the two hands sharing a card, and they fall into 2 patterns once you ignore which suit is which. Best case for AKo is 69.27% (for example A♣K♦ against A♦5♦), worst is 68.05% (A♣K♦ against A♥5♥). The headline number is the average over all 36, weighted by how many deals share each pattern.
| Example deal | Suits in common | Deals like it | AKo wins | Split | A5s wins | AKo equity |
|---|---|---|---|---|---|---|
| A♣K♦ vs A♦5♦ | K–A, K–5 | 12 of 36 | 1,146,588 | 79,044 | 486,672 | 69.27% |
| A♣K♦ vs A♥5♥ | none | 24 of 36 | 1,126,756 | 77,021 | 508,527 | 68.05% |
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. AKo wins most often with pair (32.2% of boards); A5s with two pair (8.6%). Splits happen when both hands play the same five cards or make the same hand, mostly two pairs.
| Made hand | AKo wins with it | A5s wins with it | Split with it |
|---|---|---|---|
| High card | 10.08% | 0.00% | – |
| Pair | 32.20% | 7.92% | – |
| Two pair | 15.30% | 8.56% | 2.92% |
| Three of a kind | 3.26% | 1.65% | – |
| Straight | 2.29% | 3.45% | 1.01% |
| Flush | 1.80% | 6.46% | 0.10% |
| Full house | 1.19% | 1.11% | 0.48% |
| Four of a kind | 0.06% | 0.06% | 0.03% |
| Straight flush | 0.01% | 0.07% | 0.00% |
| Total | 66.19% | 29.27% | 4.54% |
When calling with A5s is right
If you call an all-in of S with A5s and know you are up against exactly AKo, you win 31.54% of a pot that holds 2S plus whatever dead money D was already in the middle (blinds, antes, earlier bets). Calling breaks even when 31.54% × (2S + D) = S, so D ÷ S = 1 ÷ 0.3154 − 2 = 1.170. A 10 bb shove needs at least 11.7 bb of dead money before calling it with A5s 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: A5s (dealt as A♥5♥, the most common suit pattern) facing a 10 bb all-in with 2.5 bb already in the middle, against a range of exactly AKo. 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 AKo or A5s
Other domination matchups
| Matchup | First hand | Split | Second hand | Equity bar |
|---|---|---|---|---|
| AKo vs AQo | 74.4% | 4.7% | 25.6% | |
| AKs vs AQs | 71.3% | 4.2% | 28.7% | |
| AKo vs AJo | 74.1% | 4.7% | 25.9% | |
| AKo vs KQo | 74.8% | 1.2% | 25.2% | |
| AKo vs KJs | 70.1% | 1.1% | 29.9% | |
| AQo vs AJo | 73.9% | 5.8% | 26.1% |
- 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 AKo at 68.59% here, 0.13 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: ako-vs-a5s.json and the summary matchups.json, built by
tools/build-matchups.mjs.