A random football thought

In the few minutes of the football game that I watched last night, there was a sequence that would be interesting to probe further.  The Pittsburgh quarterback threw a pass to an open receiver for what would’ve been a first down but he dropped it; the next play was a pass interception. 

What I’d like to know is just how damaging is a dropped pass, or to extend the thought a bit the penalty that negates a first down.  If you think about it, a sport like football is trying to attain a balance between offense and defense so that one would suppose that getting a first down in four plays (really three in most situations) is reasonably probable but not easy.  Or to put it another way, that in a set of downs, the offense will only have so many opportunities to move the ball the required distance.  So what is the “cost” of wasting one of those opportunities?

When you watch baseball the announcers frequently mention that you can’t give a team extra outs.  In a sort of obverse way, it’s always seemed to me that teams rarely succeed twice in football.  I have no way of knowing what the true statistic is, but I’d bet that a dropped pass, or off target pass that would’ve been a first down or resulted in significant yardage is not a small error.