Let's start with the caveats: the preseason is not the regular season and it is dumb to jump to any conclusions. Fox wants basically a perfect run-pass balance (achieved last night 34-34) which probably won't hold out in the regular season. The play book and game strategy are probably intentionally vanilla.
NOW with that out of the way, one of the biggest issues for the Broncos last night was clearly third down conversions. Five of fourteen is 36%, which would have been around 20th in the league last year. That's not awful, but on a night where the team average 8.9 yards per pass attempt and 4.4 yards per rush, it's definitely a weak link.
Although the play by play doesn't support causation (the third down failures were caused by negative plays (2), drops (1), and crappy short yardage line play (1)), these third down difficulties highlighted another issue I saw last night: sub-optimal play calling on second down and long. Fox runs too much on second down. This problem is aggravated because teams generally expect a running play after an incompletion. Let's have a look at the preseason play calls (below the jump):I've defined my sample as any second down situation of seven yards or over. That's because a "successful play" on second and seven requires a gain of five yards (60% of yardage required per Football Outsiders and The Hidden Game of Football). Five yards per play is well above what can be expected for a running play, so the dominant strategy on seven or more yards should be a pass. Here is every Broncos play call on 2nd and 7+ for the Buffalo and Seattle games with their first string offenses:
2nd and 9, following Moreno 1 yard carry: Pass, Orton sacked. Third down play: Pass, incomplete.
2nd and 10, following incomplete pass: Rush, McGahee for 2 yds. Third down play: Pass, incomplete.
2nd and 10, following no gain McG rush: Pass, gain of 20 yds.
2nd and 11, following Royal rush: Pass, gain of 15 yds.
2nd and 8, following Moreno rush: Pass, gain of 13 yds.
2nd and 25, following penalty and pass: Rush, 5 yds, 3rd down play: Rush, no first down.
2nd and 8, following Moreno rush: Pass, Orton sacked, 3rd down play: Rush, no first down.
2nd and 10, following incompletion: Rush, gain of 2, 3rd down play: Pass, gain of 24.
2nd and 10, following incompletion: Pass, gain of 9, 3rd down play: Rush, no first down.
2nd and 11, following rush: Rush, gain of 6, 3rd down play: Orton scramble, no first down.
I am not including the end of half possession for obvious reasons.
2nd and 10, following incompletion: Rush, no gain, 3rd down play: Pass, gain of 15.
2nd and 10, following incompletion: Rush, no gain, automatic 1st down following penalty.
Here's where I talk:
So one thing to notice obviously is penalties and sacks can put the Broncos way behind the sticks, and give them no real chance at a first down. Discounting that, and hoping it improves in the regular season, let's look at the play selection. First, the run-pass balance on 2nd and long is 50/50. That is passing far less than the league average. The NFL as a whole throws about 60% of the time on 2nd and long. Additionally, passes are more likely to result in a positive outcome than a run on 2nd and long (see link).
We see that even in our tiny sample size of 12 plays. Of the six running plays, none were successful (gaining 60% of the yardage required for the first down). One rushing play was merely a conservative call: the 2nd and 25 situation. So the running game was 0 for 5 on second down. Out of the six passes, four achieved 60% of the yardage required for a first down. Although it does not explain the Broncos' third down difficulties last night (Orton converted two third downs from behind schedule after failed running plays, and the facemask bailed them out after another), these third and longs could be a problem going forward.
The other issue is predictability. The NFL has a tendency to basically alternate plays, and the Broncos are exhibiting this to a T. Out of 12 second an long situations, the Broncos did the opposite of what they did on first down in 10 of them. Although I'm not going to take four quarters of preseason football and say the Broncos playcalling is predictable, it is definitely something to watch for in the regular season.