We’ve all seen that despite our defense shitting the bed, Justin Herbert is back to his old self slinging the ball around like crazy and single-handedly carrying a bad team.

But what about those 4 games where Herbert was wearing a cast on his left hand? Did it affect his play?

The answer - conclusively - through the use of a mix of old-school data and advanced PFF metrics is clear: the cast on Justin Herbert’s hand massively impacted his ability.

Point 1: The PFF grades

Herbert injured his finger right at the end of the 3Q of the Week 4 matchup vs the Raiders. Since he played the majority of that game with no cast, we can group this in with his non-cast games.

CAST STATUS	PFF GRADE	RANK AMONG NFL QBs
Cast (Week 5-9)	68.2	19th among 35 QBs
No-cast (Week 1-4 + 10-11)	88.0	1st among 39 QBs

Yep, that’s right, Justin Herbert was - according to PFF - literally the best QB in the NFL this season when not wearing a cast/brace on his finger.

Point 2: The old-school stats

These figures are further backed up when we look at the more traditional metrics available to us:

CAST STATUS	GAMES	PASSING YARDS PER GAME	TOTAL TDS PER GAME	INTS PER GAME	PASSER RATING
Cast (Week 5-9)	4	230.3	1.5	0.8	87.9
No-cast (Week 1-4 + 10-11)	6	281.5	2.7	0.3	106.7

Again, more evidence here of a massive improvement in Herbert’s numbers when he isn’t wearing a cast.

Point 3: Why is this the case?

Now of course many people would argue that a non-throwing hand injury shouldn’t affect a QB, but we can see the following major differences between Herbert not wearing a cast, and wearing one. In brackets are his NFL ranks, in each case, lower numbers are better rankings.

​

CAST STATUS	Average time to throw	Average depth of throw	Pressures to sack rate	“Big time throws” %	Turnover-worthy plays %
Cast (Week 5-9)	2.80s (17/35)	7.7 yards (25/35)	16.7% (15/35)	2.6% (29/35)	3.4% (22/35)
No-cast (Week 1-4 + 10-11)	2.72s (15/39)	8.8 yards (11/39)	13.8% (11/39)	6.0% (3/39)	2.6% (11/39)

Point 4: All areas of the field

Looking even deeper we can see that Herbert is better across every passing distance, it isn’t just his deep ball that improved as many have said.

​

CAST STATUS	PFF GRADE - 20+ yards	PFF GRADE - 10-19 yards	PFF GRADE - 0-9 yards
Cast (Week 5-9)	62.4 (25/29)	79.5 (12/35)	63.5 (28/36)
No-cast (Week 1-4 + 10-11)	69.6 (22/35)	91.7 (4/40)	85.9 (1/38)

Point 5: Conclusion

Justin Herbert would be leading the MVP race if he didn’t break his finger against the Raiders - particularly in a season with fairly poor play from other big name QBs.

Sure, you have to adjust a bit that we played some slightly better defenses in his 4 game injured stretch, but that goes nowhere near enough to explain the difference in performance.