It's a bit of hyperbole to say that Iowa's run defense was bad Saturday. After all, the Hawkeyes gave up just 119 yards on 36 Indiana carries, an average of 3.3 yards per rush.
Unfortunately, Indiana ran the ball 39 times. And on those other three attempts, Iowa gave up 197 yards and three touchdowns to Hoosiers running back Tevin Coleman. They were the only three runs of over 35 yards that Iowa has conceded this year. So where was the breakdown? Let's take them in order.
RUN 1: 83 YARDS, FIRST QUARTER
All three runs had the same three key components:
1. Iowa's front seven overpursued
2. Iowa's secondary screwed up
3. Tevin Coleman is good at football
So let's start from the beginning. Iowa lines up in its base 4-3 against Indiana, which is lined up in the shotgun three-wide, with an h-back in the backfield left. Indiana runs a simple outside zone, with a pitch to Coleman.
The first sign of Coleman's excellence comes with that sidestep around the tackle of Bo Bower, but the rest of this has its roots in Iowa's own offense. Indiana does a nice job of sealing the edge, taking Mike Hardy out of the play and opening the hole. But the culprit here is middle linebacker Quinton Alston, who correctly diagnoses the outside zone and runs precisely to where Iowa runs the play, outside the h-back. Indiana didn't even need to block him, because Alston has run himself completely out of the play.
What Alston did was not good, but at least he overpursued in the direction of Coleman's initial run. The worse part is that, even after Coleman makes the cut, safety John Lowdermilk does the same thing: He runs himself into a block trying to get outside, while the running back has turned upfield inside of him. That's just poor diagnosis and not paying close enough attention to the backfield, something that hurt the Iowa secondary all day. In any case, once Coleman got past Lowdermilk, it was over. The cut was magnificent, and Iowa had no idea what to do once it happened.
RUN 2: 45 YARDS, SECOND QUARTER
The cutback is supposed to be the zone running game's weapon against overpursuit, but when you are absolutely certain it's coming, there's nothing quite like a counter play. Tevin Coleman, come on down:
Indiana backup quarterback Chris Covington had just entered his first college game, and Iowa had to expect Indiana to run the ball. Iowa was giving Alston a breather, so Travis Perry entered at middle linebacker. And Perry quickly showed why he's not playing more at middle linebacker. Hardy lost contain on the end of the line, which certainly didn't help things, but Perry lunges in the direction of the offensive line's movement on the snap:
From there, he has no chance of making a tackle on anyone. This play is over before it really began.
Bo Bower, covering a receiver at the bottom of the screen, takes a block from the H-back. Lowdermilk doesn't adjust to the counter and, as a stationary target, gets blocked ten yards downfield. The next line of defense is safety Jordan Lomax, who takes a good angle against someone not Tevin Coleman and quickly finds out that this is indeed Tevin Coleman.
But the pièce de résistance is Greg Mabin, who is below the picture on a receiver and would typically have responsibility for stopping the run to the edge. When Coleman veered outside to avoid Lomax, it should have been Mabin in position to either make the tackle or turn him back inside so that Lomax and Lowdermilk could clean up. And where was Mabin?
On a play that could have been diagnosed as a run in half a second by just watching the center, Mabin was covering a post pattern as the running back took the ball into the end zone behind him. To his credit, the Indiana receiver sold the route, going so far as to put his hands up to catch an imaginary bomb from a quarterback who had entered the game only seconds before the snap. The other cornerback, Desmond King, was closer to making a tackle.
That's...well, that's not good.
RUN 3: 69 YARDS, FOURTH QUARTER
Coleman's third run is slightly different than the other two, in that Iowa's defensive front actually did its job. Indiana had it 3rd and 4, and Iowa was again in its stock 4-3 formation.
This is another zone read, and Reggie Spearman does a capable job of working off a block and plugging the hole. Most of the time, this is where he combines with Davis on a tackle and Indiana punts. But Coleman cuts inside and throws an elbow at Davis. Let's zoom in on Big Carl:
Hardy whiffs on an attempted tackle, and we're off to the races once more. Coleman veers away from Lomax, who takes himself out of the play by first following the quarterback on the read option, then running into the block of the referee in the defensive backfield. And Desmond King, who should be out there? He was following a fly pattern down the sideline.
By the time he recovered to make a play, Lowdermilk was diving futilely at Coleman and preventing King from doing anything. That was all she wrote.
It could have been an Indiana problem. After all, the only way to let the Hoosiers back in a game like this was, presumably, through a string of long bombs. But with Sudfeld out, Iowa should have been far more focused on Coleman that it was. Overpursuit by backside defensive ends and diagnosis problems by the linebackers and, more frequently, the secondary are causing enormous problems, and while Iowa has managed to recover against Pittsburgh and Purdue, it could not when faced with a truly top-caliber halfback like Tevin Coleman. And with Ameer Abdullah, Melvin Gordon and David Cobb still on the schedule, it had better fix those problems immediately or face more of the same in November.