Here is a video of Miami reliever Carter Capps pitching. As you can see, he basically jumps off the rubber, and delivers from the front of the mound.
Apparently, MLB gave their approval to Capps's pitching style -- but with a caveat:
"They just said they wanted me to make sure I dragged my foot and not get too elevated in the air, and make sure it's more on a lateral plane," Capps said. "As long as I do that, they have no problem with it. But it was very strange."
However, as a Bleacher Report article notes:
Not to be a foot in Capps’ punch bowl, but his pitching on Monday didn’t exactly feature extensive toe-dragging. There didn't appear to be any toe-dragging, actually. And by launching down the mound, he does chop off a not-immeasurable distance between him and the plate. In a game where batters have fractions of a second to react to the ball, this difference can be significant.
Was Capps's pitching in the MIA@ATL game legal? If not, why didn't the umpires disqualify him?