Right about midfield, clearly identifies him as 'fast guy who could blow this up', runs between 18 and PK for a few strides, then throws one block (18 is smaller and clearly knows he can't out physical Kelly but he also can't outrun him) and then Jack's final move is to simply slow down and turn his back around the 15. But that all starts back at the 50 with the same guy, who probably had the angle without the right blocking.