No wonder defensive coaches tend to be the hollerin' charismatic bastard types and not the monastic, pen-chewing booth types. Overthinking the calls is pointless when the mathematics of football failure are, for the most part, on your side no matter what you call on 3rd and long, or worse, 4th and short with the national title on the line.
Brilliant call to blitz there? Yes. A play likely to fail anyway? Also, yes, thanks to the joy that only sports mathematics can bring.
RockMNation's been working on the numbers, and while this may strike you as "Man on Moon" quality stuff, we're all behind empiricism in even its tiniest forms. (We have timed the best ways to get our gym, up to and including complex variations on how to avoid a particularly thorny set of railroad tracks. There's flow charts and everything. No, the medication is NOT working.)
The Sabermetric-type methodology does add numerical backbone to what you had previously assumed to be true just because some man who'd spend a lot of time in Bike shorts had told you: that getting into third and long is real bad in numerically demonstrable ways, and that yards gained closer to the goal line remain far valuable than yards gained far away from your own goal line.
I welcome this, personally, as an empirical base that bolsters my usual emphasis on keeping the entire playbook open: outside of talent, predictability is the number one killer of offenses, and defenses that stop the run and make offenses one-dimensional are, well, see above.
To invert this, though: what does this say about defensive strategy? Given the propensity of most offenses to view first down as a running down, why not run blitz four first downs out of five? And just hang back on third down and rush three? The number of drinks we've crushed in our hand* watching a defense lay back on third down only to give up a square in remains countless, but given the numbers, isn't that the safest bet against most passing sets, since most offenses will, when dared to save themselves with a pass, drop the elephant gun of probability and blow their own head off?
It's testament more to the gnat's attention span of our own brain and, we suppose, most fans in that you don't remember when the mathematically probable strategy works. We saw an interview with Norm Chow once where, in discussing play design, he said the most important thing he could emphasize was humility. "You don't know what's coming. You can't." Humility, for him, meant understanding that the most important down was first down, and that your play design had to have the kind of flexibility built into it to mitigate chaos hurtling in from the defensive side.
On the defensive side, the howling void of probability and numbers may be even more daunting. On third down, the offense might have some ideas on how to craft a play to beat several defenses, drawing up routes to accommodate two or three possibilities. However, the "success" or "failure" of a particular defense may be even more arbitrary, as the offense could grant you a freebie due to incompetence no matter the call. The defense can grant the same to the offense on third down, sure, but the chances are lower since, by assignment, the defense is less flexible on a passing down than the offense.
So, if you're curious as to the practical applications of this, go to a casino. Do you have "a system" for beating the roulette table? Have you really convinced yourself that you have a statistical advantage over the dealer at a blackjack table? Do you sit at the table nervously, speaking to no one and trying to remember what that important bit of verbiage on re-raise bets was from page 37 of Doyle Brunson's Super System? Congratulations, your football sign is offensive coordinator. You are doomed to misery and a lifetime of hand infections from writing too many plays down with an ungloved hand. Enjoy.
If you are doubling down on a pair of twos, garrulously chatting to everyone within earshot, and double-fisting drinks even though the cards are getting blurry and you don't recall where you put your last three thousand dollars...well, congratulations to you, too. You are a defensive coordinator by temperament. Look forward to being fired for giving up 3rd and 16 despite winning a conference title with the exact same blitz package three years earlier. Either way, feel free to get your yaw-yaw on, you blitzmeister you.
*Plastic cups only, of course. If our hands could crush fine crystal and glass, we'd be out making ducats on the Professional Arm Wrestling circuit--in between stints as a long-distance trucker trying to win back the love of his son.