Ultimate Big O

It’s like Big O, except there are two boards

Big O is Omaha Hi-Lo with five hole cards. Ultimate Big O keeps that, and deals two separate boards instead of one: a top board and a bottom board, each with its own flop, turn and river. You still make hands from exactly two hole cards and exactly three board cards, but now you get to pick which board to take those three cards from.

The WSOP rule sheet calls it “Ultimate” because of how the pot is divided. There are only two halves, one for high and one for low. The best high hand on either board gets the high half, and the best qualifying low on either board gets the low half. It’s not four ways.

30-second cheat sheet

• Five hole cards each. Two boards, each with a flop, turn and river: ten board cards total.
• Each hand uses exactly two hole cards plus exactly three cards from one board. Never mix cards from the top and bottom board in one hand.
• Half the pot to the best high, on either board. Half to the best 8-or-better low, on either board.
• Your high and low can come from different boards and different hole-card pairs, or both from the same board.
• No qualifying low on either board? The best high wins the whole pot.
• The WSOP caps it at 8 players.
• Ask whether the table plays “best/best” (this game) or board-by-board four-way splits. They’re different games with similar names.

Full rules

The deal

Standard Big O deal: blinds (or ante-and-blind combinations as in other WSOP button games) and five hole cards each, then preflop betting. The WSOP says the game “follows all standard Big O rules” with the two-board modification. That’s why there’s no separate betting-structure line in the rule text. Big O itself is normally played pot-limit, and limit versions show up in mixed rotations.

The two boards

The dealer deals a double board: two sets of community cards, one above the other. Each board gets a three-card flop, a turn and a river, so there are ten board cards when it’s done. Betting rounds happen after the flop, turn and river as in any Omaha game.

The WSOP’s burn rule for this game is: one burn before the flop, and no burn before the final card if it completes the board. The reason, which is our own arithmetic and not a quote from the WSOP, is that at eight players the deck runs out of cards: 40 hole cards, one burn, six flop cards, one burn and two turn cards leaves exactly two cards for the two river cards. At seven or fewer players the deck isn’t exhausted. The WSOP’s text for how the second board’s cards are placed is written for its high-only Double Board Omaha game (no extra burn between the boards), and we’re assuming this game follows the same procedure.

WSOP also says the game “may also be played as a bomb pot variant,” meaning everyone antes and there’s no preflop betting. The text doesn’t give any further procedure for that, and the separately listed WSOP 5 Card Double Board Bomb Pot PLO is a different, high-only game. See Bomb pot.

Building your hands

For each half of the pot you build a five-card hand from exactly two of your five hole cards and exactly three cards from one of the two boards.

• High: the best five-card hand using the usual poker rankings.
• Low: five different ranks, none higher than 8, aces low, straights and flushes ignored. The wheel is the nuts.
• You can use the top board for your high and the bottom board for your low, or both from the same board. You may use the same hole cards for both or two different pairs.

Dividing the pot

• The player with the best high hand on either board takes half the pot.
• The player with the best qualifying low on either board takes the other half.
• One player can win both halves, which is a scoop.
• If no one has a qualifying low on either board, the best high takes the whole pot. If only one board can make a low, the low half is contested only on that board.
• Ties split their half. The odd chip goes to the high hand in a hi/lo split under the WSOP’s general rule. The WSOP text doesn’t spell out the odd-chip rule for a tie inside one half of this specific game, and its mixed-game procedure for button games says worst position.

Counterfeiting across boards

Your low is judged against the best low anywhere. Holding A-2 doesn’t guarantee the nut low, because the other board may give another player a better or equal low. A board that pairs your ace or deuce counterfeits you on that board only. You may still have a good low on the other one. A tie for best low, even across boards, splits the low half.

Rooms disagree

• Best/best or four-way. The WSOP and Cardplayer Lifestyle’s Mixed Game Festival rule list use the best/best split described here (see best/best). Steve Badger’s strategy page describes double-board hi-lo as commonly split four ways, with each board getting its own high and low half. He notes that splitting a low three ways on one board gets you 1/12 of the pot. This page follows the WSOP.
• Betting structure. The WSOP inherits Big O’s structure, which is normally pot-limit. A Two Plus Two thread title and Mixed Game Festival-style usage include limit double-board Big O in mixed rotations. We only saw the thread in a search snippet.
• Burn procedure. The WSOP describes the second-board procedure only for its high-only game. The Ultimate Big O entry states only the flop burn and the completing-river exception.

How you’ll embarrass yourself

• Picking whichever board looks best and ignoring the other. You only need some board to give you the best low, and a different board can give you the best high.
• Mixing top and bottom cards in one hand. Illegal. Three from one board.
• Using any number of hole cards other than two. Still exactly two.
• Assuming A-2 is automatically the nut low. The other board can hand somebody else a better or equal low, and your own board looking great doesn’t change that.
• Forgetting that there may be no low at all. If neither board has three distinct cards 8 or lower, high takes it all.
• Confusing it with 5 Card Double Board Bomb Pot PLO. That one is high-only and split by board.

Lore and reputation

Ultimate Big O appears by name in the 2026 WSOP Live-Action Rules, with the eight-player cap. Cardplayer Lifestyle lists “Double Board Omaha Ultimate High/Low (Best/Best)” among the variants played at its Mixed Game Festival. We found no 2026 WSOP bracelet event titled “Ultimate Big O,” so its WSOP presence appears to be as a Dealer’s Choice option. Which Dealer’s Choice events actually use it is unconfirmed.

A Two Plus Two thread titled “Starting Hand Tips for Double Board Limit Big O” suggests limit double-board Big O has been played in casinos, but we only saw it through search snippets. Steve Badger notes double-board games are “most commonly played as part of a mix of games,” so typically seven-handed at most.