To me pushing a roll is best if the character describes what they are doing, and understanding the drawbacks. My players fight to push rolls, and are bummed when either I don't let them roll at all, or when the single success is needed.
Pushing as a mechanic is always about over reaching, giving it all you've got, going beyond what you've done before, trying something, anything, to do more. The risk taking and getting out on a limb sometimes hurts. When you break yourself you don't roll on the crit charts, but you make it easier for a foe to take advantage of your condition and do that extra damage that will place you in mortal danger.
Working into the narrative the heroics that were attempted, the probable successes that were achieved by pushing this or using your pride if even after a push you didn't get a success has made some of the most rewarding stories that are retold by my group time after time. Nothing better than breaking yourself, your weapon, and delivering the crit blow to the adversary by rolling your pride. Doesn't happen often but it is perfect when it does.
Really that's why WP is so beautiful as a mechanic, it rewards gutsy play and lets you know ahead of time if the push will cause problems (if there are banes showing).
Indeed. I've started to require
my players to describe what they're doing when they push a roll - though they're not taking it very seriously yet.
I may eventually rule that if a player can't come up with a reasonable in-game description of what they are doing different
, for justifying the extra dice, they're not allowed to push that roll in particular.