I got berated at the table for this......

[TStoneMBD]

ishmael, there are 2 players in the hand.

if it was heads up and you knew the opponent had a straight, you would not cap the flop unless you could get a free card a reasonable amount of time.

however, 3 handed, if you knew both of the opponents hands and saw that your pot equity is 33%, you could cap just for the hell of it while your equity would be neutral.

in the long run, top pair with a jack high flush draw has far more than 33% equity in a 3 way pot. that is why you cap. not only are you building equity but you are also positioning yourself for a free card.