To believe or not to believe? That will be the question for the Chicago Bears' front office this offseason.

Down the stretch, Mitchell Trubisky gave the offense life. With Trubisky starting, they scored 30 or more points in 4 of the final 6 games, helping earn their second playoff berth in three seasons.

Then the team absolutely flopped in said playoffs, putting up just three points before an irrelevant, final-play touchdown.

With Trubisky set to enter free agency, the Bears have a decision to make: do they trust the production down the stretch or hit the reset button yet again?

Based on the teams they faced during the uptick, they need to be massively skeptical of what Trubisky did.

The NFL is a small-sample sport. With just 16 games each regular season, you don't have time for things such as opponent strength to even out. That's especially true for situations like the Bears' where they used multiple quarterbacks, which just whittles the sample even more.

This makes it important to account for the schedules players faced during the regular season so that we can properly evaluate them entering 2021. Doing so last year would have allowed us to be skeptical of Carson Wentz, Sam Darnold, and Gardner Minshew while buying low on Baker Mayfield.

To do this, we'll be leaning on numberFire's Net Expected Points (NEP). This is the expected-points model we use at numberFire, tracking the expected points added or subtracted on each play throughout the year. For quarterbacks, Passing NEP includes deductions for expected points lost on negative plays such as sacks, incompletions, and interceptions. The player-level numbers are unadjusted for schedule, but the team-level numbers are.

This means we can look at the season-long numbers for each defense and use that as a baseline for how an average quarterback would have been expected to perform against them. An average drop back against the Los Angeles Rams was worth an expected -0.03 Passing NEP while one against the Detroit Lions was worth 0.34. The league average here was 0.13.

By weighting the number of drop backs each quarterback had against each defense, we can generate an expected Passing NEP per drop back for each player. The lower the expected Passing NEP, the tougher the schedule, and vice versa. We can use that not only to glean who had the toughest and easiest schedules but also to see who outperformed expectations based on the teams they faced.

The Bears' front office will want to take notice.

After making those calculations, here are the marks for each quarterback this year who had at least 100 drop backs. They are sorted by schedule from toughest to easiest based on their expected Passing NEP per drop back (xPass NEP). If their difference is positive, it means they outperformed expectations based on the schedule they faced. The Pass NEP column just shows their raw Passing NEP per drop back for the full season.

Not only did Trubisky face the easiest schedule in the league, but nobody else was even close. Trubisky didn't record a single drop back against a top-12 pass defense the entire regular season.

The playoffs were different. The New Orleans Saints finished the year ranked third against the pass, meaning it was far and away the toughest assignment of the season. Trubisky was hurt badly by his supporting cast in that game, so he doesn't deserve the blame for the loss. But the ease of his road in the regular season stands.

As you'll see on the table, Nick Foles is on the other end of the spectrum, having faced the second-toughest schedule in the league. That doesn't means he was better than Trubisky; Trubisky underperformed expectation by 0.06 whereas Foles missed his expected mark by 0.16. Trubisky was the better option for the team. But it does mean his regular-season numbers are tainted, and that should be factored into any analysis about whether to buy into Trubisky if he winds up leading the Bears' offense again in 2021.

The other relevant name on this list for 2021 is Taysom Hill. Hill could be in line to inherit the Saints' starting job next year if Drew Brees retires. We did get a four-game sample on Hill at quarterback, and he was a bit below average at 0.10 Passing NEP per drop back in that time. But based on the schedule he faced, you would have expected him at 0.17. Hill did some nice things, and strict Passing NEP does not account for his value added as a rusher, but he's another player for whom the schedule is a hyper-relevant piece.

The toughest schedule in the league belonged to Daniel Jones. That may be surprising given the ineptitude of the NFC East, but it truly was a tough road.

Of Jones' 493 drop backs, 54.56% came against top-10 pass defenses; only 18.05% were against bottom-12 units. Only Joe Flacco and Andy Dalton had fewer cake situations. It was definitely a rough assignment for Jones, and that matters.

That doesn't mean you can fully write off Jones' struggles. His Passing NEP per drop back was still 0.10 below expectation after you account for his schedule. In the soft matchups he did get, Jones still averaged just 0.10 Passing NEP per drop back, well below the league-wide mark of 0.22 in that split. He still didn't have a good year; it's just a bit more forgivable once you realize what he was up against.

Seeing both Jimmy Garoppolo and Nick Mullens at the top of the list should inspire confidence around the San Francisco 49ers' offense for 2021.

The team did struggle along this past year, and it's possible they make a change at quarterback as a result. However, they still ranked 11th in schedule-adjusted passing efficiency, and that's before you account for playing large chunks of the schedule without George Kittle, Deebo Samuel, and Brandon Aiyuk. The infrastructure is in place for that to be a good offense as soon as next year. If they get a proven quarterback in place, we should be bullish on most pieces tied to them as a result.

Finally, the schedule is noteworthy when discussing the performance of Tua Tagovailoa relative to Ryan Fitzpatrick. Fitzpatrick outperformed Tagovailoa even when you account for schedule, but the gap gets smaller with that context. Tagovailoa also had Preston Williams for just a game and a half and had to operate at times without DeVante Parker and Mike Gesicki.

This doesn't mean Tagovailoa lit it up, nor does it mean the Dolphins shouldn't look into a quarterback with the third overall pick. At such an important position, it is imperative that you're always exploring all options available. It does show, though, that the deck was stacked against Tagovailoa at times, meaning it's a bit of an apples-to-oranges comparison to look at his numbers next to Fitzpatrick's.