I get this overall sense that on 3rd downs, regardless of yardage needed (unless its in inches or goal line) a majority of teams throw it. Even deeper theory is this, why run the ball and have the play either get blown up or come short? If I pass it, the qb drops back to throw, ok good, but will all of these new rules that nobody can call consistently, the odds of positive yardage are better to throw. Will my QB get the questionable roughing the passer call? (odds are even HIGHER if you are a face of the NHL ala Brady, Rogers, etc), maybe the DB will hold the WR or interfere with him, or heck there is a chance for a targeting call. I don't think coaches actively think this way, but it has to be subconscious thoughts there. Pretty sad that on any given pass play you have higher chances of getting positive yards from penalties rather than just having the play executed.
Would love to try and run the numbers on that. Someone collect the data, I have SPSS through school right now and we could analyze the trends, lol
Teams use these trends to forecast what plays the offensive call is in certainl situations.. I remember Gruden talking about calling plays during garbage time just to offset trends.