Jared Goff tossed a perfect game Monday night.

The Detroit Lions quarterback completed 18 of 18 passes for 292 yards and two touchdowns during a 42-29 win over the Seattle Seahawks at Ford Field.

Yet, the former No. 1 overall draft pick of the Rams did not finish with a perfect passer rating.

“Did I not?” Goff said when informed of the statistical anomaly during his postgame news conference. “Yeah, I don’t know. That system’s weird.”

Against the Seahawks, Goff set the NFL record for most passes during a game without an incompletion, surpassing Kurt Warner‘s 10-for-10 outing for the Arizona Cardinals in 2005. Goff’s overall stats for the night, however, were only enough for a 155.8 passer rating out of a possible 158.3.

Last month, Arizona Cardinals quarterback Kyler Murray became the most recent quarterback to achieve a perfect passer rating against the Rams, completing 17 of 21 passes for 266 yards and three touchdowns with no interceptions.

So, clearly, more goes into the passer rating than just completion percentage.

Goff was sacked three times by Seattle, including once for a safety late in the game. Also in the fourth quarter, Goff had an incomplete pass erased from the books by an offensive pass interference call on teammate Brock Wright.

But none of that factors into a quarterback’s passer rating.

The stat that prevented Goff from receiving a perfect rating was percentage of touchdown passes per passing attempt. The minimum for passer rating perfection is 11.9%, and Goff came up a tad bit short at 11.1%. Oddly enough, he actually would have received a perfect rating had he attempted two fewer passes.

Speaking of oddities, the Lions did achieve a perfect passer rating as a team, and Goff played a key role in the play that put them over the top. Midway through the third quarter, Goff caught an eight-yard touchdown pass — the first touchdown reception of his career — from receiver Amon-Ra St. Brown.

So, yeah, it was a pretty incredible game for Goff, who was somehow overlooked when coach Dan Campbell handed out game balls. The coach instead gave them to receiver Jameson Williams, safety Kerby Joseph and offensive coordinator Ben Johnson before sheepishly admitting to reporters that he hadn’t realized Goff had completed all of his passes.

“I just gave the game ball to somebody else, so I feel awful right now,” Campbell said when informed about Goff’s stats. “I knew he played a heck of a game. I did not realize he was perfect. I did not know he was literally 18 for 18, but I knew he played really well. You could feel it.”

Told by reporters about Campbell’s remorse for not giving him a game ball on such a special night, Goff laughed.

“That’s OK,” he said. “I’m just happy we got the win.”