Big O is also called five-card Omaha or Omaha-5. A variant of poker close to Omaha, Big O is a favorite among players because of the significantly increased action it generates.
Big O plays mostly like Omaha, but rather than playing with four-hole cards (i.e. cards dealt to the players, which they keep close to their chest), players of Big O work with five.
And Just like in Omaha, players must use exactly two of their hole cards at showdown and exactly three of the board cards to put together the best possible five-card poker hand.
Big O is played in limit or pot-limit forms and can be played either for high only or as a hi-lo split game, usually with an eight qualifier (as you would also have in Omaha).
The key difference between Big O and Texas Hold’em is in the hole cards. In Texas Hold’em, each player gets two-hole cards, while in Big O poker, each player receives five-hole cards.
Robert Turner, 1993 WSOP bracelet winner and inventor of Omaha, said in a 2016 interview that “Big O poker is like Omaha on crack,” because of the increased betting action players enjoy in any given hand.
Because players are given five-hole cards (instead of four in the case of Omaha, or two in the case of Texas Hold’em), the game is simpler in terms of math. Also, straight flushes and sets are far more common in this game than in games like Texas Hold’em.
A hand of Big O can be played by at most nine players, each with five cards, with all cards dealt before the flop. (The flop being the reveal of the first three board cards.)
Just like in Omaha and Texas Hold’em Poker, there are four betting rounds:
1. The pre-flop: right after the cards are dealt, with each player now having five-hole cards.
2. On the flop: right after the reveal of the initial three board cards
3. On the river: right after the reveal of the fourth board card
4. On the turn: right after the exposure of the fifth and final board card
In the limit betting structure, the bet size doubles on the last two betting rounds.
At showdown, active players must use exactly two of their hole cards along with exactly three of the board cards to form the best possible poker hand.
In many Big O games, there’s also a hi-lo element, which means that you can also form the lowest possible hand as well. A low hand must have all cards lower than 8 to qualify. In a Big O hi-lo game, the pot is split between the player with the best high hand combination and best low hand combination
This means games can go in many ways, and betting can go with both high hands and low hands. There’s certainly a lot more options for players when it comes to playing their hands, allowing for more bets, and thus, more fun.