Granted, it's not a high bar relative to teams with more to speak of at the position, but it's still meaningful for such a feat to occur for an inexperienced pro in the first year of a new system and that it saw him lead them to 12 wins.
The catch-all statistic QBR is designed to measure more than just passer efficiency, also taking into account the value of rushing, total turnovers and penalties. It has its detractors, as does any single objective standard for the game's most scrutinized position, but we'll start there.
Mitchell Trubisky was fourth in QBR in the NFL in 2018 at 72.8, behind Patrick Mahomes (82), Drew Brees (81.9) and Ben Roethlisberger (73). That number is tops for the Bears in the 10 years it has existed, followed -- unsurprisingly -- by six seasons from Jay Cutler, the undisputed top quarterback ever for the team.
Using passer rating, the only Bears quarterbacks ahead of Trubisky didn't sustain their fine work long enough to qualify. Josh McCown had a 109 passer rating when he started five games in 2013. Sid Luckman played in 11 games but started just three in throwing 202 passes when he had a 107.5 passer rating in 1943. Brian Hoyer had five starts and a 98 rating in 2016, and Jim McMahon's 1984 season ended after nine games, a lacerated kidney suffered against the Raiders and a rating of 97.8.
That means Trubisky's 95.4 passer rating is tops, surpassing Luckman's 95.3 in 1941 in which he only made 113 (!) throws, the 93.7 from both Rudy Bukich in 1965 and Billy Wade in 1961 and Erik Kramer's 93.5 in 1995.
Applying the eye test is impossible when we do historical comps, and while our most recent evidence from Trubisky on Sunday was typical of his year -- passes floated into dangerous spots too often, some accuracy issues and then strings of brilliant and gutsy play -- we're unable to make such judgments retroactively in a fair way for these other players.
Pro Football Focus has proprietary instruments that attempt to balance the reward a passer provides as a function of risk, a concept that shows Trubisky to have been among the less valuable in the game this year. And there's never anything wrong with allowing for some new ideas in this effort. But we'd have to run all the other Bears quarterbacks through that machine as well.
With what's easily available to us, it's not a stretch to place Trubisky's 2018 at the top of the list for a team with an underwhelming legacy at the quarterback spot, only to expect marked improvement from here.
The best ever can still not be good enough.