Ranking low hands in Omaha hi/lo poker is very different from ranking high hands. While high hands take into account five-card combinations like a straight or a full house, qualifying low hands are ranked in accordance with its individual card values. And the lower the value of one's high card in a qualifying low hand, the better.
Since suits and value sequences have no bearing in ranking low hands, a qualifying low hand showing a flush or a straight doesn't exclude it from the low rankings. Under these circumstances, they may vie for the high end of the pot and its low end as well.
There are two prerequisites to qualify as a low hand in Omaha hi/lo poker. Using two from one's four hole cards and three from the five on the board, a five-card low hand mustn't contain a pair. Also, the individual values of the five-card hand must not go over eight.
There are over 50 combinations of qualifying low hands. But regardless of the single card combinations between ace and eight, the weakest low hand is one with a single eight. Single high cards on each qualifying hand are compared and low valued numbers always beat the higher numbered cards in ranking low hands in Omaha hi/lo poker.
Take a five-card low hand with an eight, five, three, two, and an ace. If that's compared with another player's low hand with a seven, six, five, three, and two, each of the hand's high card is taken into account. Since the first player's high card is an eight while the second player's high card is a seven, the latter wins half the pot because, certainly, seven is lower than eight.
In case of a tie with the highest card in low hands, the second highest ranking card in qualifying hands is used. If a tie still exists, the third highest card is used and so on. Let's say you have a six, five, three, two, and an ace. The other player has a six, five, four, two, and an ace. You're tied at six and you're tied at five. The next high card is your three and other player's four. Since three beats the four in ranking low hands in Omaha hi/lo poker, you'll win half the pot.
By comparing individual high cards between qualifying low hands in Omaha hi/lo poker, the best low hand is determined and awarded half the pot. Simply put, the lower the value of a player's high card, the better its position is in the ranks.