ATTACK — F

Ouch. Bo Nix’s debut got off to a slow start and didn’t improve much as the afternoon wore on. He threw for just 67 yards in the first half, had one interception and four others that easily could have been. Nix didn’t impress with a string of big plays in training camp and the preseason, but he did a good job protecting the ball. Seattle’s defense had him off balance from the start.

Every time Denver’s run game got going, head coach Sean Payton seemed to pull it off. But fumbles by Audric Estime (recovered by Denver) and Jaleel McLaughlin (lost in the third quarter) certainly didn’t help in attempts to control the flow of the game.

In short: this was a failure from start to finish.

DEFENSE — B-

The Broncos defense had one hiccup in the first half, but otherwise played great. They harassed Geno Smith. They got an interception from Alex Singleton. They forced two safeties in the first half. The new defensive line paid off immediately, and the duo of Jonathon Cooper and Baron Browning looked powerful from the side.

As has been the case all too often in recent franchise history, this group had little margin for error against Seattle. When the group got leaky in the second half — Kenneth Walker ran for 81 yards in the third quarter alone and the Broncos had a coverage bust on the first play of the fourth — the game was out of reach.

SPECIAL TEAMS — A-

The area where the Broncos excelled on Sunday. The rule change before kickoff didn’t generate much excitement, but Denver’s punt team made a couple of big plays. The biggest: a botched punt recovered at the 9-yard line, giving the offense first-and-goal. Just as important: Tremon Smith made a big play at the end of a Riley Dixon punt, killing him at the 1-yard line for the second of a pair of first-half safeties for the Broncos.

COACHING — V

The defense came out strong. Special teams were on point. But the offensive game plan didn’t work from the start.