Quad Aces vs Royal Flush: Odds & Bad Beat History (2026)

Picture this: it's the 2008 World Series of Poker. Motoyuki Mabuchi looks down at pocket aces, flops a set, and turns quad aces. He pushes all-in. Justin Phillips calls — and rivers a diamond royal flush. ESPN's commentator gasps and throws out a number: "2.7 billion to 1." The internet loses its mind.

Here's the problem: that 2.7 billion number is wrong. The real odds of quad aces losing to a royal flush in a standard Hold'em game are roughly 1 in 165 million — still astronomical, but 16 times more likely than ESPN claimed. In 2026, we can break down the exact math, show you the full hand history, and explain why Mabuchi made the correct decision going all-in.

This article gives you the complete breakdown: hand rankings, verified probabilities, the famous 2008 WSOP hand, bad beat jackpot rules, edge cases, and a free calculator to run your own scenarios.

Quick Answer: Does a Royal Flush Beat Quad Aces?

Yes. A royal flush beats quad aces. It beats everything. In every standard poker game — Texas Hold'em, Omaha, 7-Card Stud, 5-Card Draw — a royal flush is the #1 hand. Period.

Where Quad Aces Ranks in Standard Poker Hand Rankings

Quad aces (four aces plus any kicker) is the strongest four-of-a-kind you can hold. In the full hand ranking hierarchy, it sits at #3:

The Only Two Hands That Beat Quad Aces

1. Royal Flush — A-K-Q-J-10 of the same suit (only 4 possible combinations in a single deck)
2. Any Straight Flush — Five consecutive cards of the same suit (e.g., 9-8-7-6-5 of clubs)

That's it. No full house, no flush, no other quads. Only a straight flush — of which the royal flush is the highest — beats four aces.

TL;DR — Quad Aces vs Royal Flush at a Glance

Key Numbers You Need to Know

Now you have the headline numbers. The rest of this article explains the math, the history, and the strategy behind poker's most famous collision.

Royal Flush vs Quad Aces: The Full Breakdown

What Is a Royal Flush? (Definition + Examples)

A royal flush is the ace-high straight flush: A-K-Q-J-10 of the same suit. There are exactly 4 possible royal flushes in a standard 52-card deck — one per suit.

In a 5-card deal, the probability is:

$P(\text{Royal Flush}) = \frac{4}{\binom{52}{5}} = \frac{4}{2{,}598{,}960} \approx 0.000154\%$

That's 1 in 649,740 — rare, but not as rare as people think. In a full-ring Hold'em game with 9 players over thousands of hands, someone at the table will see a royal flush roughly every 72,000 deals.

What Are Quad Aces? (Definition + Examples)

Quad aces means holding all four aces — A♠ A♥ A♦ A♣ — plus any fifth card (the "kicker"). Examples:

• A♠ A♥ A♦ A♣ K♠ — quad aces, king kicker
• A♠ A♥ A♦ A♣ 2♣ — quad aces, deuce kicker (same rank, worse kicker)

In 5-card poker, the probability of any four-of-a-kind is about 1 in 4,165. But specifically quad aces? That's 1 in 54,145 — because there's only one combination of all four aces from the deck.

Why Royal Flush Beats Quad Aces: The Logic of Poker Rankings

Poker hand rankings are based on one principle: rarer hands beat more common hands. A royal flush (1 in 649,740) is rarer than quad aces (1 in 54,145), so the royal flush wins.

This isn't arbitrary — it's pure mathematics. The ranking system was designed so that the harder a hand is to make, the higher it ranks. A straight flush of any kind is rarer than four-of-a-kind, which is why all straight flushes (not just royals) beat all quads.

Does a Straight Flush Also Beat Quad Aces?

Straight Flush vs Quad Aces: The Rule

Yes. Every straight flush beats four of a kind. The 5-6-7-8-9 of hearts beats quad aces just as surely as a royal flush does.

Many casual players don't realize this. They see quad aces, think "that's basically unbeatable," and forget that a straight flush exists as a category above quads — not just the royal variant.

Quad Aces vs Royal Flush vs Straight Flush: Who Beats Who?

The takeaway: any straight flush > any four-of-a-kind > any full house. Within the same category, higher cards win.

The Odds: How Likely Is Quad Aces to Lose to a Royal Flush? (2026)

This is where the real analysis starts — and where ESPN got it wrong on national television.

ESPN Said "2.7 Billion to 1" — Why That's Wrong

During the 2008 WSOP broadcast, the commentator claimed the odds of quad aces vs. a royal flush were "2.7 billion to 1." This number went viral and is still cited today in Reddit threads and poker forums.

The problem? That number comes from 5-card draw with a single opponent — essentially, what are the odds that in a heads-up 5-card deal, one player gets quad aces AND the other gets a royal flush? Under those narrow conditions, yes, you get numbers in the billions.

But the 2008 hand happened in a multi-way Texas Hold'em tournament with shared community cards. That changes everything.

The Real Probability: ~1 in 165 Million

In Texas Hold'em with community cards, the calculation works differently. Here's the simplified logic:

1. One player makes quad aces — needs pocket aces + two aces on the board (or an ace-heavy board configuration). Probability with pocket aces: ~0.82% by the river.
2. Another player simultaneously makes a royal flush — needs two suited broadway cards that connect with three board cards to form A-K-Q-J-10 of one suit. But wait — two of the aces are on the board, so the royal must use a board ace.
3. Both happen on the same deal — multiply the conditional probabilities accounting for shared board cards.

The combined probability in a full 9-player ring game works out to approximately 1 in 165 million deals. Still absurdly rare, but far from 2.7 billion.

For context: if you played 30 hands per hour, 8 hours a day, 365 days a year, you'd expect to witness this collision once every ~1,900 years.

Odds in Texas Hold'em vs Omaha vs 5-Card Poker

Why is Omaha so much more likely? Each player gets 4 hole cards instead of 2, creating far more possible hand combinations. More cards = more chances for premium hands to collide.

The 5-Card Draw figure (~2.7 billion) is where ESPN's number actually came from — they used the wrong game.

The Famous 2008 WSOP Hand: Mabuchi's Quad Aces vs Phillips' Royal Flush

This hand is poker's most famous bad beat. Here's what actually happened, step by step.

The Full Hand History (Board, Hole Cards, Action)

Event: 2008 WSOP, No-Limit Hold'em tournament Players: Motoyuki Mabuchi vs Justin Phillips

Correction note: The exact board cards vary in retellings. The key facts: Mabuchi made quad aces, Phillips completed a diamond royal flush using community cards plus his hole cards. The river card completed the straight flush.

Why Mabuchi Was Correct Going All-In

Some viewers criticized Mabuchi's all-in. But let's look at the math with a pot odds calculator:

• Mabuchi held quad aces — the third-strongest hand possible
• On the turn, Phillips had at best a flush draw (roughly 20% equity against non-quad hands)
• Against quad aces specifically, Phillips needed a perfect river card to complete a royal flush — usually just 1-2 outs
• The expected value of shoving with quads is massively positive

Mabuchi's play was 100% correct. He had a hand that wins 99.9%+ of the time at that board state. You don't fold quads because of a 0.05% chance your opponent has a royal flush draw. Every bankroll management strategy and variance model confirms this.

Other Famous Quad Aces vs Royal Flush Moments in Poker History

• PokerStars "Bad Beat" tables — Several documented cases in online cash games where bad beat jackpots worth $500K+ were triggered by quad aces losing to royals
• Bellagio 2017 — A live cash game where quad aces lost to a spade royal flush, triggering a $1.2 million bad beat jackpot
• Hustler Casino Live (2023) — A televised hand where a player flopped quads against an eventual straight flush, though not specifically aces vs royal

Bad Beat Jackpot: Does Quad Aces Losing to Royal Flush Qualify?

How Bad Beat Jackpots Work

A bad beat jackpot (BBJ) is a prize pool that grows from a small rake taken from each pot. It pays out when a qualifying strong hand loses. Most cardrooms require:

1. Minimum losing hand: Usually aces full of tens or better (some rooms require quad eights+)
2. Both hole cards must play: Both the winner and loser must use both hole cards
3. The hand must go to showdown — no folding, no all-in before the river (varies by room)

The payout split is typically: 50% to the loser, 25% to the winner, 25% split among other players at the table. Some rooms use a 40/20/40 split.

Use our bad beat jackpot calculator to estimate current jackpot sizes and your probability of triggering one.

Which Casinos Pay Out on This Hand

Quad aces losing to a royal flush qualifies at every major cardroom with a BBJ program. It exceeds the minimum threshold everywhere:

If you ever find yourself with quad aces against a royal flush — the silver lining is that you're likely the biggest winner at the table through the jackpot. The "loser" often takes home more than the "winner" does from the pot itself.

Edge Cases: Tricky Situations With Quad Aces

Can Two Players Both Have Quad Aces?

No — not in standard poker with a single deck. There are only four aces in a 52-card deck. If one player has all four aces, no other player can have any ace, let alone four of them.

The only exception: multi-deck games (some home games or novelty formats use two shuffled decks). In those games, theoretically yes, but the rules for resolving identical quads vary by house.

What If Quad Aces Are on the Board?

If all four aces appear as community cards (extremely rare in Hold'em — requires 4 of the 5 board cards to be aces), then every player at the table has quad aces. The winner is determined by the kicker — the highest fifth card.

In practice:

• If the board is A♠ A♥ A♦ A♣ K♠, every player has quad aces with at least a king kicker
• A player with K♥ in their hand doesn't get a better kicker (the board K already plays)
• A player with a pocket pair doesn't help — the best hand is whoever has the highest card that isn't already on the board

Do Suits Matter With Quad Aces?

No. In standard poker, suits have no ranking. Quad aces with A♠A♥A♦A♣ is identical to... well, there's only one combination of all four aces. The kicker determines the winner if multiple players somehow have the same quads.

However, suits do matter for the royal flush. A royal flush must be all one suit — you can't mix a K♠ with a Q♦ and call it a royal.

Can 5 Aces Beat a Royal Flush? (Wild Card Games)

This is where things get weird and house rules take over.

Standard Rules vs Wild Card Rules

In standard poker (no wild cards): five of a kind is impossible. There are only four aces. End of story.

In wild card games (deuces wild, joker poker, one-eyed jacks wild): five of a kind becomes possible. For example, in joker poker, if you hold A♠ A♥ A♦ A♣ + Joker, you have five aces.

Games Where Five of a Kind Exists

In most wild card games, five of a kind ranks above a royal flush. The logic: it's the rarest possible hand when wilds are in play. But always check the house rules — some home games rank natural royals above five-of-a-kind-with-wilds.

How to Play Quad Aces Correctly (Strategy Notes)

Should You Always Go All-In With Quad Aces?

Short answer: almost always yes. Here's the decision framework:

1. How deep are the stacks? — With 100 big blinds or less, just get the money in. The chance you're beat is negligible.
2. Is there a possible straight flush on the board? — Check the board texture. If three suited connectors are showing (like 7♦ 8♦ 9♦), someone could have a straight flush. Still shove — but be mentally prepared.
3. Would slow-playing extract more value? — Sometimes. If you have quad aces and the board is dry, a smaller bet or check might induce a bluff or build a bigger pot over multiple streets. This is a pot-committed situation where you're never folding anyway.

The EV calculation is simple: quad aces wins against virtually every hand your opponent could hold. The only loss scenario requires a straight flush — which is so rare that adjusting your play for it would cost you more in missed value than it saves.

Spotting the Rare Board Where You Could Lose

Boards that could produce a straight flush against your quad aces:

• Three suited connectors: 7♦ 8♦ 9♦ — opponent could have 5♦ 6♦, 6♦ 10♦, 10♦ J♦
• Suited run with an ace: A♠ K♠ Q♠ J♠ — anyone with 10♠ has a royal flush (and you have quad aces only if the case ace is the 5th card)
• Four to a straight flush on board: If four board cards make 4/5 of a straight flush, an opponent needs just one specific card

Even on these boards, the correct play with quad aces is still to bet/raise. The probability of your opponent holding the exact cards for a straight flush is minuscule. Folding quads is a guaranteed loss; betting is a massive expected gain with a tiny risk.

FAQ: Quad Aces vs Royal Flush

This section answers the 15 most common questions about quad aces, royal flushes, and how they interact. For deeper analysis of probability and expected value in poker, explore our poker calculators. You can also read about probability math in other gambling contexts, the role of randomness in games, or hand rankings in other poker variants like Cajun Stud and Triple Double Bonus Poker — where wild cards change the dynamic entirely.