I am not a coach at all, but I did study a few running plays last night in slo mo because they went so badly (and plus there were commercials
). I actually saw some good holes being opened, but no running back to fill them. By the time the running back got to the holes, they were gone. I can speculate that the line is not holding their blocks long enough, but it looked more like a timing error. The backs seemed to get the ball so far back in the backfield that by the time they got to the line the holes had closed. I would suggest moving them closer to the line and working on the timing. FWIW.