Jared Cook - Catch rates

It seemed like a post was in order to bring the Jared Cook hype train back to earth (it was going so fast that it achieved escape velocity).  Sure, Jared Cook has had 6 different quarterbacks over the last 3 years with the Rams, but let's actually see some number before we conclude that poor quarterback play has been holding Cook back:

With the QB's career completion rate on the x-axis as a point of reference, the plotted point estimate (with 95% confidence intervals ) is Cook's catch rate under the listed quarterback in every game that this QB played exclusively.  In order to get this posted in a reasonable time frame, I excluded games with multiple QBs as that would have required I dig into all the play-by-play data.  The reader is welcome to look into those games to see if they drastically change the numbers listed here:

QB	Passes	Catches
Bradford	37	22
Clemens	41	25
Hill	42	21
Davis	43	25
Foles	53	27
Keenum	19	10

Still, for the purpose of being thorough, we might also want to compare Cook's aggregate catch rate with all other Rams pass-catchers over the last 3 years:

	Passes	Catches
Rams	1494	901
Cook	259	142
Not Cook	1021	628

We see that Cook's catch rate (142/259 = 54.8%) is quite a bit lower than other Rams (628/1021 = 61.5%).  One can apply a Chi-square test to see if this difference is large enough to be systematically different or if it may just be a chance driven and find the p-value was marginally significant (p < .10).  Note that Cook's NFL catch rate with the Rams is not significantly better (p=0.721) than his college rate (71/140).

While I suppose it's possible that all these numbers are simply reflective of the fact that QB chemistry is more important for the the tight-end positions than other pass catchers, but these numbers make me think that Jared Cook is not destined to have a break-out year, even if it is Aaron Rodgers is throwing him the ball.