Former NFL quarterback Hugh Millen analyzes three reasons for the Seahawks’ victory, including Jimmy Graham’s 30-yard touchdown reception.

Thanks to Chicago Bears coach John Fox for dragging that three-tight-end, goal-line offense out of the 1952 playbook for the first half Sunday. We’ll never get those 90 minutes back.

The Seahawks, after sorting out gap responsibilities inherent in that scheme, ultimately held the Bears to their half of the field for all but three of Chicago’s 46 plays. The Seahawks seem comfortable muddling through peanut butter in the first halves of games before some facet of the team eventually takes control.

A few thoughts:

• Running from under center: A major portion of Seattle’s running game has been from shotgun formation, with Marshawn Lynch aligned to either side of quarterback Russell Wilson. With an ailing Lynch, Seattle still amassed 159 rushing yards, highlighted by Thomas Rawls with 104, and an adjustment was evident. For all of Seattle’s runs, excluding Wilson’s scrambles and two failures to get a yard on third down, the Seahawks averaged a healthy 5.2 yards on their five shotgun runs for 26 yards.

Under center, however, the Seahawks had 16 attempts for 106 yards and a 6.6-yard average. Seven plays featured Derrick Coleman as a lead fullback, and Seattle gained 53 yards, with a 7.6 average. From the I-formation, the Seahawks were able to achieve favorable blocking numbers to the weakside of the formation and Coleman had a few devastating blocks on linebackers at the point of attack. The stretch play, a staple in Seattle’s zone blocking, is further augmented by the lead blocker. The cost of operating from the I-formation is that two of the five eligible receivers are aligned behind the quarterback and are thus unable to vertically stretch the pass defense — and can stretch the pass defense laterally only by a swing route from the tailback.

Checkdowns from either back in the I-formation allow for late influence on zone coverages, but the passing game generally involves naked bootlegs or play action with deep or intermediate throws to tight ends and wide receivers.

• Tyler Lockett kickoff return: Lockett’s return highlighted a resounding victory in the kicking game for Seattle. Richard Sherman’s “gotcha” punt return set up Seattle’s first field goal (points which, until Lockett’s return, seemed vital) and Steven Hauschka remained perfect with his field goals and forced touchbacks on five of six kickoffs.

On the Lockett return, there were too many good blocks to mention, but of particular note was the blocking scheme executed by Ricardo Lockette: As Bears safety Brock Vereen closed on Lockett, Lockette’s beautifully timed trap block drew the fine line between an ambush block from the side and an illegal block-in-the-back/clip.

• Jimmy Graham touchdown catch: Ahead 13-0 with 4:28 left in the third quarter, Seattle aligned in a double-set (two receivers to each side of the formation) “squeeze” alignment. Graham was aligned on the left side, close to Lockett. Such a formation allowed Graham and Lockett to crisscross their release, with Lockett releasing inside on his “shallow cross” route and Graham then releasing outside.

The route combination that followed, “Flanker Drive,” was former 49ers coach and general manager Bill Walsh’s favorite because the shallow cross first attracts the underneath coverage, while the “Basic Cross” (in this case the in-route by Graham) trails the shallow at the intermediate level — 13 yards on this play. (An additional shallow cross from the opposite side by Jermaine Kearse provided a further “Mesh” combination, which is particularly effective against man-to-man coverage).

Flanker Drive has been effective against all coverages, including the “man under” that Chicago played. Vereen would have help in his bump-and-run, man-to-man assignment by fellow safety Adrian Amos, who was positioned high on that half of the field.

In theory, Vereen would tightly cover Graham with such over-the-top help, but after Graham’s outside release, Vereen, who didn’t aggressively jam Graham due to the threat of a “pick” in this formation, jumped outside, giving the Seahawks’ tight end favorable inside leverage to run his in-breaking route.

The combination of good scheming and athletic route running resulted in three full steps of separation for Graham, but also credit Wilson’s athleticism. This coverage almost always features a four-man rush, but because the underneath defenders are in man coverage, it is vulnerable to a running quarterback. As a consequence, linebacker Shea McClellin feigned a rush, then “spied” Wilson and the Bears offered just a three-man rush. That allowed Wilson to patiently wait while Graham won his matchup. Game over.