Colin Kaepernick is the new starting quarterback for the San Francisco 49ers.

Head coach Chip Kelly made the call on Tuesday afternoon after stating the team would review the quarterback situation following Thursday night’s 33-21 loss to the Arizona Cardinals.

There’s been a lot of attention surrounding Kaepernick this season, though none of it was due to anything he’s done on the field. Some believe that attention was keeping him off the field, but the biggest factor in now getting him on the field in 2016 is how bad Blaine Gabbert has been as the starter.

Gabbert's Gone

Through five weeks of the NFL season, there have been 30 quarterbacks who have dropped back at least 100 times. Of those quarterbacks, only one has been worse than Gabbert by our Net Expected Points (NEP) metric -- Case Keenum of the Los Angeles Rams.

Keenum has been worse in both Passing NEP and Passing NEP per drop back, but Gabbert has the lowest Success Rate -- the percentage of plays that positively impact NEP -- of any quarterback at just 37.5 percent.

Gabbert has rated well through some stats like ESPN's QBR this season that factor in quarterback rushing, but Gabbert’s gains on the ground have come more from panicked running than designed runs one would expect from a Chip Kelly offense.

And even though Gabbert has the most rushes by a quarterback this season, he’s still second in Rushing NEP behind Aaron Rodgers, who has 17 fewer carries, and he’s only sixth in Rushing NEP per attempt among 15 quarterbacks who have carried the ball at least 10 times this year.

Factoring in his rushing and passing, Gabbert ranks 28th in Total NEP among the 30 quarterbacks with at least 100 drop backs.

Throwing the ball has been a different adventure. Gabbert hasn’t just been bad in the ways bad quarterbacks are usually bad -- he’s really been on another level. The 49ers don’t have an overwhelming amount of talent at the wide receiver position, but there’s enough there to get players open within the offense.

That hasn’t really mattered, though, because Gabbert hasn’t been able to hit them when it’s happened. Just take a look at San Francisco’s first offensive play against Arizona from Thursday night when Gabbert missed a wide open Garrett Celek. This was a typical Gabbert throw from 2016. (Video courtesy NFL Game Pass.)

That arguably wasn’t even his worst opening play of 2016. That likely goes to running a zone read with no running back in the backfield against the Seattle Seahawks in Week 3.

The Blaine Gabbert experiment has been embarrassingly bad for the 49ers, and a change needed to be made.

Going Forward

Now the reigns get handed to Colin Kaepernick, who was also not performing well the last time we saw him as a starter.

Among 46 quarterbacks who dropped back at least 100 times in 2015, Kaepernick ranked 40th in Passing NEP per drop back. He’s now two and a half seasons removed from his last productive turn as a starter when he was ninth in Passing NEP per drop back in 2013.

Kaepernick also gets a tough go in his first start against a Buffalo Bills defense that has been hitting its stride of late. The Bills rank 9th in Adjusted Defensive NEP per play and 13th in Adjusted Defensive Passing NEP per play.

What Kaepernick will get on his side for his return is a helpful running game. The 49ers rank 11th in Adjusted Rushing NEP per play, led mostly by Carlos Hyde. It’s also helpful that Chip Kelly’s run schemes have looked far more helpful to Hyde’s strengths so far this season with less horizontal running that led to the struggles with the Philadelphia Eagles last season. Hyde is currently 12th in Rushing NEP per attempt among the 25 backs who have gotten at least 50 carries this season.

It’s still unknown what Kaepernick will look like in a Chip Kelly-style offense, but it’s hard to imagine it’s going to be any worse than what Gabbert showed during the first five weeks of the season.

There has been promise in the San Francisco offense, but it was erased by the failures of the starting quarterback. Receivers are getting open, and all Kaepernick has to do is hit them. It sounds easy enough, but Gabbert wasn’t able to do it, and that’s why this move had to be made now.

There’s no guarantee Kaepernick returns to his 2013 form, but the 49ers at least needed to see if he can be better than the quarterback production they’ve gotten to start 2016.