I like to look at rookie contract QB’s in this way because it shows their most recent full length season, Will continue to do this ever game until the end of the year.
Do not take this as an endorsement for or against keeping him.
The last 17 games tracker:
The Good: His last 17 games he is at 4200 total yards and 33 total td’s, 93.2 rating.
The bad: 5 fumbles lost and 12 picks. About a 2:1 TD to turnover ratio. Sacks: 62, about 3.5 per game.
His first 17 games:
Justin Fields has a passer rating of 73.2 with 2,549 yards, 10 touchdowns and 14 interceptions in 17 games in his first 17 games in his career.
You can’t give players unlimited time to grow though, in a not so distant future fields has to be paid and QBs get paid big money. If the guy you pay is not THE guy you end up with a Daniel Jones contract that severely puts your time in a bind. Even if Fields is just average it’s hard to put together an amazing team with an average guy on a big contract taking up such a large portion of cap space.