There’s no doubt Sunday was a step forward by the Bears’ offense, but it was a modest one. The Bears scored all three of their touchdowns in a stretch of three possessions during their 20-13 win over the Lions, and the rest of the game was far from perfect. Of their other nine drives, seven were three-and-outs, and just one ended beyond midfield. Outside of the three touchdown drives, Mitch Trubisky was 6-for-11 for 40 yards. Here’s a closer look at the good and the bad from a film review of the game:

Sacks still an issue

Trubisky was sacked five times for a total loss of 28 yards, but not all of those were on his offensive line. He’s getting sacked nearly three times per game, which remains a problem.

On the first one, on second-and-six at his own 25, he waited nearly five seconds after the snap before Lions linebacker Devon Kennard took him down. Kennard beat right tackle Bobby Massie, but Massie held him off for a solid three seconds, which is good enough.

That sack put the Bears in third-and-nine, and they punted one play later.

The next one can’t be pinned on Trubisky. New center Cody Whitehair bounced a snap midway through the second quarter, and there was little Trubisky could do once he picked up the ball. Whitehair had several low snaps in his first game after shifting from left guard.

Third-down sacks aren’t particularly monumental because the team will punt if it fails on the conversion anyway, and four of the Lions’ sacks on Trubisky came on third down.

All but one of those was on third-and-long, when he might as well try to make a play until the last possible moment, but there was a brutal sack on third-and-one with 8:12 left in the fourth quarter.

With the Bears up 20-6 and having a chance to close out the Lions with a scoring drive, coach Matt Nagy called a pass rather than try to muscle for a yard on the ground. Nagy didn’t want to say what went wrong on that play, but Trubisky scrambled and missed a chance to hit a wide-open Allen Robinson for three or four yards and a first down.

Third-down failures

The Bears are the fourth-worst third-down team in the NFL, converting only 29.8 percent of their plays. They went 2-for-12 against the Lions. They were 11th last season, by the way, at 41 percent.

That statistic, good or bad, is typically attributed to quarterback play. In this case, very few of the Bears’ shortfalls on third down were Trubisky’s fault.

Of the 10 failures to convert, the pocket collapsed almost instantly on four, and one was doomed by a low snap.

Trubisky also had a third-and-six conversion lined up until Taylor Gabriel dropped the pass. One was a run play to eat clock, and another would’ve been a third-and-nine conversion except that tight end Trey Burton narrowly missed getting two feet down before sailing out of bounds.

Trubisky played decent overall on third downs but couldn’t overcome the many mistakes around him.

Three terrific touchdowns

All three of the Bears’ touchdowns were great plays.

Trubisky lobbed a perfect pass to backup tight end Ben Braunecker as he laid out near the left edge of the end zone to go up 7-6 in the second quarter.

He barely did anything on the next one, but he didn’t need to. The beauty of Tarik Cohen is that he can do most of the work by himself, and he did so by turning a harmless swing pass into a nine-yard touchdown to open the third quarter.

Cohen caught the pass in space about seven yards behind the line of scrimmage and blew past Lions cornerback Rashaan Melvin on the left sideline.

The final touchdown came on the next possession, when Gabriel ran away from cornerback Mike Ford just past the line of scrimmage and got loose for a 24-yard catch. It wasn’t a pretty throw mechanically by Trubisky, but he hit Gabriel in stride and made it an easy reception.

Forgettable day for Fuller

Kyle Fuller is one of the best cornerbacks in the NFL and was an All-Pro last season, but Sunday was not his day. He was flagged for holding, unnecessary roughness and pass interference.

The worst was the unnecessary-roughness call for his hit on Lions quarterback Jeff Driskel late in the first quarter. Driskel scrambled for five yards and slid, and Fuller flew in and lowered his shoulder near the end of the play.

Driskel slid late, and Fuller appeared to be trying to make a legal, shoulder-to-shoulder hit, but he hit him partially in the helmet. Fuller erupted at the officials and had to be restrained.

He also grabbed the back of referee Carl Cheffers’ shirt while yelling and pointing at the screen, which easily could have gotten him ejected. Cheffers, showing some grace, was the best break Fuller caught Sunday.