Poker online players typically have different size stacks, so that a large bet from a big stack surpasses the entire chip stack of another player. But just because a player does not have enough chips to match a bet, that player with the smaller stack can still enter the pot.
In this situation, the dealer creates a “side pot” in addition to the main pot. The main pot holds all the chips the small stack put in plus equal amounts of chips from the larger stacks who called the big bet. The side pot contains the chips from each player that exceeded the amount bet by the short stack who could not match the bet.
The short stack is only eligible to win the main pot and cannot claim any chips from the side pot. Those players still remaining continue to bet into the side pot. The all-in short stack can no longer bet.
Side pots can seem confusing to new online poker players, but dealers are accustomed to this situation and can usually calculate the side and main pots quickly. They simply subtract the amount of the all-in bet amount from the bigger bets and put those chips into the main pot.
The betting continues and if a large bet causes any other players with cards to fold, then that bettor wins the side pot. If several contenders remain for the side pot, then once the betting is finished, those eligible for the side pot show their hands and the best hand wins the side pot.
Then the all-in player, who is eligible for the main pot, reveals. If the all-in beats the side pot winner’s cards, then the all-in gets the main pot. If the side pot winner has a better hand, that player gets all the chips and the small stack is eliminated. Keep this in mind when you play poker online.