I mean, are you ever sure? I think his ability to achieve slightly above-average results with below-average QB talent is indicative of good coaching. I’m also a believer that O-line play at the NFL level can be coached up more than play at other positions can, so I’m especially inclined to give Reich and his staff credit for that.
I feel very confident that Chris Ballard is a really good GM. I don't feel amazing about Reich, despite his reputation.
It's interesting that in 5 seasons he'll have had 5 different primary QBs.
2018 - Andrew Luck
Team went 10-6. Luck had an average season for him & then retired.
Beat the Texans 21-7 in Wild Card round before losing 31-13 to the Chiefs.
2019 - Jacoby Brissett
Team went 7-9, 7-8 in games Brissett started. Jacoby had a very similar statistical season to his 2017 year albeit slightly better & much less sacks).
2020 - Philip Rivers
11-5. Rivers had an average year for him & then retired.
Lost 27-24 to Bills in the 1st round.
Reich was panned for inconsistent playcalling & potentially leaving 10 points on the field.
2021 - Carson Wentz
9-8. Wentz had an average year for him. Blew a game against the Jaguars in Week 18 they didn't even show up for, keeping them out of the playoffs.