The truth is it hardly matters. In the long run, both will lose.
Long term, the immediate winner of a quarterback battle that is sure to dominate NFL headlines inside and outside of Chicago all summer won't likely win a lot on the field and almost certainly won't keep the job anyway.
There'll be a lot of noise. Already is.
Trubisky—the 2017 No. 2 overall pick trying to save his job in a contract year—is "motivated" by the presence of Foles, who won a Super Bowl MVP with the Philadelphia Eagles, tanked magnificently as a member of the Jacksonville Jaguars and is now a Bear.
Chicago quarterbacks coach John DeFilippo—who will presumably play a major role in assessing Trubisky and Foles in camp—wants to see "juice" from the eventual winner, whatever that means. And new Bears wide receiver Ted Ginn Jr. believes Trubisky can stave off the more highly-paid and more accomplished veteran.
Prepare yourself now for weeks of wild speculation and even wilder bluster.
But all we know for certain is the Bears consider it to be an open competition, and we can deduce from their actions—they declined Trubisky's fifth-year option for 2021 soon after acquiring Foles for a fourth-round draft pick—that they might believe Foles has a better chance of becoming the solution for them at the sport's most important position.
But because the pressure is so high for the Bears to succeed right now considering their expensive, aging roster, and because they've invested so heavily in both Trubisky and Foles, the fate of this quarterback battle feels obvious. One will "win" the competition this summer, his leash will be impossibly short, he'll be replaced the moment he remotely struggles, and then the "loser" will experience the same turbulent ride.
Despite high expectations after making clear progress as a sophomore, Trubisky averaged an NFL-low 6.1 yards per attempt while running the league's fourth-lowest-scoring offense last year. And it probably wasn't a fluke.
The Chicago offense was often pretty conservative in 2019, but Trubisky was also one of the least efficient deep passers in the league, and he was even worse on said throws in his "breakout" 2018 season. Among 27 quarterbacks who have attempted at least 100 passes that have traveled 15-plus yards in the last two years, only Josh Allen of the Buffalo Bills has a lower rating on said passes than Trubisky.
"There wasn't too much of a difference between Trubisky's 2018 and 2019 seasons on a throw-for-throw basis," wrote Pro Football Focus' Steve Palazzolo, disturbingly, "but he received far more help from playmakers and had better overall luck in 2018."
Even under those circumstances, the 2018 Bears offense ranked 20th in terms of DVOA (defense-adjusted value over average) at Football Outsiders and Chicago failed to experience postseason success.
Meanwhile, outside of two outlying runs in 2013 and 2017, Foles has been a mediocre NFL quarterback. Those hot streaks can't be ignored, but it's important to acknowledge that neither was sustained for very long.
He posted a ridiculous 118.6 passer rating in an 11-game span to close out the 2013 regular season, but he was the league's seventh-lowest-rated qualified passer in 2014. Following a trade to the then-St. Louis Rams, he was even worse on paper in 2015, and beyond that, he journeyed to Kansas City and eventually back to Philly as a backup.
Foles again got hot—and at the perfect time—when he led the Eagles to a title in place of an injured Carson Wentz in 2017. But even then, he completed just 54 percent of his passes in three regular-season starts. He struggled as the team's Week 1 starter in 2018 and threw four interceptions in two playoff games in relief of an again-injured Wentz in that year's postseason.
Foles performed so poorly when healthy in Jacksonville that the Jags gave up on him after just four starts. Less than a year after guaranteeing the former Super Bowl hero more than $50 million, Jacksonville decided it was better off with 2019 sixth-round pick Gardner Minshew II, who completed fewer than 60 percent of his passes and posted a sub-90 passer rating in the final month of his rookie campaign.
Among 42 quarterbacks who threw at least 100 passes in 2019, only five averaged fewer than 6.5 yards per pass attempt: Pittsburgh Steelers backup Mason Rudolph, Detroit Lions backup David Blough, Miami Dolphins backup Josh Rosen, Foles and Trubisky. And while Foles' four-start sample size is small, his yards-per-attempt average dating all the way back to 2015 is just 6.4. Trubisky's rate-based numbers were better in his first two seasons, but significant regression in a 15-start third season is almost as discouraging as an alternative in which he was always bad.
Neither passes the "What have you done for me lately?" test, but a broad look at the rate-based numbers isn't any more encouraging.
In the last six seasons, 39 quarterbacks have attempted at least 1,000 passes. The only members of that group with lower passer ratings during that span than Trubisky are Foles, Joe Flacco, Brian Hoyer, Josh McCown, Blake Bortles and Brock Osweiler.
Come the fall, all except one of those guys will either be a backup or out of the league. The other will lead the Bears into battle against the Detroit Lions on September 13.
If each remains relatively healthy—also a concern considering that Foles has never started more than 11 games in a season—both Trubisky and Foles will almost certainly see plenty of action this year in Chicago. But there's considerable evidence that neither is likely to succeed. When that inevitably happens, the organization will try to forget Trubisky was ever a Bear and will reembark on the seemingly never-ending pursuit of a franchise quarterback.
Foles might linger into 2021, but only because—per Spotrac—it'd cost the Bears $15.7 million to cut him next offseason. The brass will soon realize that's no reason to delay a new quarterback search, because, like Trubisky, it's extremely unlikely that the 31-year-old can experience sustained success in Chicago or elsewhere.
Jay Cutler couldn't get it done, and Kyle Orton wasn't the answer. Neither was Rex Grossman nor Jim Miller nor Cade McNown nor Jim Harbaugh. It's only a matter of time before Trubisky and Foles join that list. The future at quarterback isn't on the current Bears roster.
The longer it takes for the team to realize that, the longer the suffering will continue for a fanbase that hasn't experienced a playoff victory since 2010.
Brad Gagnon has covered the NFL for Bleacher Report since 2012. Follow him on Twitter, @Brad_Gagnon.