If the river is dealt once, there are two possible outcomes:

This means that Player B has a chance of winning the pot of 22.7% if the board is only dealt once. Player A has the lead, but Player B has 10 outs. The reason for dealing the board multiple times when going all-in is simple: It reduces the chance of losing the all-in and increases the chance of winning a portion of the pot. What Exactly Happens When Running it Twice? It is also possible to deal the turn and river on earlier betting rounds or even the entire board two or more times when going all-in before the flop. Occasionally, players may also agree to deal the river three or four times, and the pot is divided according to the number of their respective wins.

If Player A wins once and Player B wins once, the pot is split. Likewise, if Player B wins twice, he gets the entire pot. If Player A wins both times, he gets the entire pot. If the players agree to run it twice, the river is dealt twice. Player A has a set and Player B has a straight flush draw and exactly 10 outs (any diamond except the Six and Five and any Nine). Let’s take a look at a simple example: Two players are all-in on the turn with the board showing Q ♦ 8 ♦ 6 ♠ 5 ♣. In general, weaker players should insist on running it only once, while stronger players benefit from reduced variance and multiple runs.

The expected value does not change at all when running it twice or more often.

Running the board multiple times reduces variance.

TL/DR: For the impatient readers, those are the answers to the questions:

1 2 vs 1 3 poker