Couple of interesting spots in Omaha with paired boards.
Hero has AAxx against villain's T987
Flop comes T92.
Villain is ahead with 2-pair.
Turn is a 3.
River pairs the 2 (Board is T9232)
Hero's 2-pair (AA22x) now beats Villain's 2-pair (TT99x).
In Hold'em, when the river puts a second pair on board (say T4TJ4) it makes it more likely that someone can make a full house (any T or 4 in their hand).
In Omaha, the river double-pairing the board makes it
less likely someone has a boat.
On that T4TJ4 board, anyone who can make a boat (T4xx, 44xx, JJxx) could already make it by the turn (although 44xx is now promoted to quads).
But if the river was, say, a 7, so the board is T4TJ7, anyone with T7xx, 77xx just filled up.
More proof that Omaha isn't Hold'em.