Omni’s point is a good one: it’s harder to develop two QBs at a time than just one. There are abstract psychological concerns (“looking over my shoulder”), and also the simple logistical problem of how to get them both the practice reps and the playing time they need to grow. Not impossible, but drafting two of them makes it harder for each.
Also, the hypothetical math of the situation is against you. One could say colloquially, “Hey, we drafted two QBs, we doubled our chance to get a good one!” But, of course, you didn’t. Assume for simplicity’s sake that we’re not worried about degrees; i.e., a guy develops into an above average QB, which is what we’re after, or he doesn’t. Also assume that the QB you draft at #22 is slightly more likely to succeed than the one you draft at #35.
These are the Quarterbacks drafted between the 15th and 42nd overall picks from 1980-2010. I’m going to say that only 12 of 34 were what we’d call a success (Joe Flacco and Chad Pennington are in, Jason Campbell is out). That’s 35%. (Since 1990 it’s been just 27%; ouch.)
Maybe we feel that this is a deep draft and our guys this year, Manziel and Bridgewater, are actually better than the typical QB from this cohort. Let’s assume that Manziel has a 45% chance to succeed, and Bridgewater has a 40% chance. There’s a 33% chance that they both crap out. There’s an 18% chance that they both succeed, but that second success doesn’t really help you very much: it improves his trade value a little and puts a quality backup on your depth chart, but basically getting the starting QB is all that matters (which is why we decided to forgo a good prospect at another position in the first place).
That leaves a 67% chance that at least one of the QBs will succeed. That’s pretty good, but you were already at 45% after Manziel. Bridgewater, who came with a very high opportunity cost, therefore effectively has only a 22% chance to succeed for you. The second QB in this scenario is only half as valuable as the first.
And that’s assuming that **Omni **& I are wrong about the possibility of two QBs getting in the way of each others development. If 10% of each QB’s good outcomes are soured by the unusual situation, you’re down to a 62% chance to land one or more successes, etc.
Obviously there’s some faux-precision in the math here, in the face of many uncertainties and complicating factors. Probably I should’ve just saved everyone some time and said, “Hey, don’t forget about diminishing returns.” But it was fun looking at the draft history.
*** As an aside, once you get past its first ten picks the 2nd Round is a total wasteland when it comes to QBs. Jeff Hostetler and Kordell Stewart are easily the best of the bunch (out of 25 since 1980). You actually get a higher proportion success stories from the 3rd or 4th Round then from the mid-late 2nd.