I mentioned in my position-by-position review on Monday that the Bears defensive front was switching its normal gap assignments in the run game to help penetrate the Redskins offensive line. I thought today I’d look back at that in a bit more detail and see just how Kyle Shanahan and his Washington offense adjusted to end up with a successful running attack.

Chicago set out to stop Alfred Morris and the stretch running game. They would often line up in a “4-3 Over” front, where the defensive line shifts to the strong side of the offensive line.

This is a typical 4-3 Over front. The offense has two tight ends on the right side of the line, indicating a run to that side. So the defensive line shifts to that side. One defensive tackle lines up over the weak shoulder of the center in the weak A gap. That allows the other defensive tackle (playing as a 3-technique) to line up over the outside shoulder of the strong side guard, which in this case is right guard Chris Chester.

This would be the normal gap assignment of a 4-3 over front. The 3-technique would attack the B gap between Chester and right tackle Tyler Polumbus. The other defensive tackle would drive the center towards the right of the line and squeeze the A gap for the linebacker to fill. But Chicago switched the gap assignments of the linebacker and 3-technique defensive tackle.

The 3-technique tackle will reach back inside and crash the A gap between the center and guard. The linebacker will then come across and cover the B gap.

Initially, this worked with great success. Bears defensive linemen were playing in the Redskins backfield for large parts of the first half.

Chester is forced to try and cut off the defensive tackle, which leaves a big hole in the B gap for the linebacker to come in and clean up.

But Shanahan caught on to this and made some adjustments to keep the Bears honest. The read option was used to get an extra blocker on the play side and help cover the A gap better. But Shanahan didn’t stop there. He mixed up his run calls, using a rare power run.

This time, Chester will pull from his right guard position while the rest of the offensive line down-blocks. Chester will then act as a lead blocker.

The Bears defensive tackle attempts to reach the A gap, but Will Montgomery blocks down and covers the gap as Chester pulls.

The defensive line gets blocked down out of the play. Chester comes across to kick out a linebacker and give Morris a running lane. He picked up six yards on that run.

Shanahan continued to vary his running plays to combat the Bears’ gap switch. He went to one of his best running plays last year, the counter.

This time, the Redskins line up with their tight end to the left. The Bears, anticipating a stretch play to the left, shift to their 4-3 Over front and try to use the same gap exchange that we saw earlier. But the offensive line will down-block to their right.

Chicago was expecting a stretch run to the left, but the offensive line blocked to the right. This takes away the defensive tackle’s ability to reach the A gap, allowing Kory Lichtensteiger and Trent Williams to block him effectively.

Morris then cuts back across the line on the counter and finds a hole to break up field for another positive gain.

The last adjustment Kyle Shanahan made was to run the stretch game, but to the weak side of the offensive line.

Once again, Chicago anticipates a stretch run to the strong side of the line, so they call for their gap exchange.

But like on the counter play, the A gap is unreachable as the play runs away from the 3-technique defensive tackle. The linebacker is also taken out of the play as his first movement is to the wrong side of the play.

Washington is able to seal the edge for Morris, who takes it 18 yards on a big gain.

With the variety of plays Kyle Shanahan used, the Bears were forced to play more honest and stop using their gap exchange quite so frequently. That allowed Washington to regain control of the game and run for 209 yards despite a slow start.

Mark Bullock is The Insider’s Outsider, sharing his impressions of the Redskins’ play without the benefit of access to the team.

What’s ahead:

● The Redskins begin practicing to prepare for Sunday’s game in Denver at 1 p.m.

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