By Dan Durkin–

(CBS) The Bears let an inferior opponent hang around far too long Sunday and got burned in the end. The fact of the matter is, the game should never have never gone to overtime, but it did.

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As San Francisco wide receiver Torrey Smith streaked down the sideline uncovered on a 71-yard touchdown reception in overtime, leading to their improbable 26-20 win at Chicago, one question was on everyone’s mind: How was he so wide open?

Clearly, there was a miscommunication and a coverage bust on Smith’s long touchdown.

A defense divides the top of the field into quarters, thirds or halves. When you see a team playing with a single-high safety after the snap, the team is playing one of two coverages — Cover-1 man free or Cover-3. Bears safety Chris Prosinski was lined up in a single-high look after the snap.

The next indicator of whether it’s zone or man coverage is where the eyes of the players in coverage are focused. In man coverage, a pass defender’s eyes are focused on the receiver he’s assigned to. He reads his hips to get a read on his pattern as he matches him down the field. In zone coverage, a defender’s eyes are fixed on the quarterback, who will take him to the ball. Peripherally, a defender scans his zone to see by whom and where it’s being threatened.

On Smith’s touchdown catch, the Bears were in a Cover-3 zone coverage, but the issue was the deep third on the offense’s left and defense’s right was left uncovered. There was a clear miscommunication between cornerback Tracy Porter and safety Adrian Amos on who was supposed to carry Smith deep down the field.

Let’s use some All-22 footage to take a closer look at the play.

The 49ers came out in 21 personnel in a slot left formation, with their running backs in an offset I-formation. Anquan Boldin is the No. 1 receiver and Smith is the No. 2.

The Bears responded with their base personnel in a 3-4-4 alignment.

Porter recognized something from the formation and tries to relay a coverage communication to Amos prior to the snap, but the call is missed.

(All images courtesy of NFL GamePass)

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Porter

The 49ers run a smash concept with Boldin and Smith. Boldin runs a deeper curl route at 18 yards, while Smith runs a corner route.

1

Amos is focused on Smith, who runs straight up the seam before giving a slight inside stick to freeze the deep safety (Prosinski) momentarily before making his break to the corner.

2

Amos’ eyes are still fixed on quarterback Blaine Gabbert and is playing underneath coverage, assuming he has help over the top, which he doesn’t. Smith is left all alone in the deep-third to catch the game winner.

3

Here’s an animated .gif of the play in its entirety.

Full

After the game, Smith had this to say about the play.

“We were just reading the (slot) corner (Amos),” Smith said. “I kind of saw him settling, and the saying is, ‘You’re even or leaving.’ We were about even, so I knew I was going to be wide open.”

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Dan Durkin covers the Bears for CBSChicago.com and is a frequent contributor to 670 The Score. Follow him on Twitter @djdurkin.