"Our inability to stay balanced was our biggest obstacle today." - Mike McCarthy, after the loss to the Lions.
That quote should scare every Green Bay Packers fan because only someone who didn't watch the game would say such a thing and head coaches are supposed to watch the game. For one thing, though Rodgers dropped back 29 times compared to 22 attempted runs, these numbers were essentially even before the very end of the very last possession. Moreover, I argue that some Platonic 50/50 split between passes and runs for its own sake is a monumentally bad idea. Football is based on exploiting matchups and on game theory. You run your base plays until the defense starts to move someone out of position at which point you exploit the area that was weakened by the move. You want to focus on your opponent's weaknesses as much as possible, while running just enough plays at their strengths to keep them honest.
"Balance" as a 50/50 split is almost never a good idea, and against the Detroit Lions it is particularly stupid as they have an unbalanced defense. They excel against the run while having consistent trouble in the secondary. The best way to attack the Lions is to throw and throw and throw, and if they drop an extra man or two into coverage or bring a big blitz, then counter with a run every now and then. The worst way to attack the Lions is to pound a power back directly into the line (Editor's note: or to run him to the boundary repeatedly when linebackers are shedding blocks with ease), creating long third down after long third down. The Packers repeatedly attempted to pound the ball and despite everything else that went wrong, I believe that this is what ultimately cost them the game.
Football Outsiders tracks the stat of "RB Success Rate". You can find it in the last 2 columns here. Success rate looks at one thing: Did this run make it more likely that your team will pick up a first down? If so, it's a success and it doesn't matter if it's a 4-yard carry or a 40-yard carry. It treats them the same. (Note: one of their other stats, DVOA, adjusts for big plays if you care about the difference between a 4 and 40 yard play.) The point is that if you run on 1st and 10 and only pick up 1-3 yards, that is not substantially better than an incomplete pass.
Against the Lions, Eddie Lacy had 11 carries, and 7 of those carries resulted in gains of 3 yards or fewer. 5 of them resulted in 0 yards or fewer. Currently, Eddie Lacy's success rate sits at a pathetic 31%. Most good running backs are above 50% with several around 70%. (Editor's note: this measure obviously takes into account run blocking as well as the play of the running back himself.)
The only running back with as many carries as Lacy who has "succeeded" less frequently is Donald Brown at 23%. I actually looked at Lacy's success rate before the game, and believe it or not, it actually went up from 28% to 31%. The point is that an integral part of the Packer strategy on Sunday was taking a RB who was getting stuffed with regularity and repeatedly running him at a defense that stuffs RBs with regularity. If you pursue that strategy in the name of "balance" you probably shouldn't be running an NFL offense.
Back to the Lions. The Lions are especially good at making sure you don't have a bunch of successful runs, meaning that much of the time you run, you will simply end up with a lost down. Aaron Rodgers currently has a 63% completion rate and is averaging 10.9 yards per completion. Those numbers are a bit down for him, and negative plays can and do happen on passing plays as well, but if you have a player completing 63% of his passes for over ten yards a completion, giving him three opportunities through the air is very likely to result in a first down, while giving him only two is far less likely. And while those numbers are actually low for Rodgers, paradoxically, you want a struggling quarterback to throw just as much against the Lions, if not more. The reason for this is that a struggling quarterback will need more opportunities per first down to be successful. In short, against a good run defense if you have a great quarterback you should throw a ton because your quarterback is great. If you have a mediocre quarterback you should still have him throw a ton to give him more chances per set-of-downs for a completion, and to keep him out of truly bad situations, like third and 10+ yards.
Lacy and WPA
Just how damaging were the runs by Lacy? In the game log for each game Pro Football Reference provides the win probability change before and after every play.
Using this we can take a look at just how damaging Lacy (and the running plays) were. We can also use the Advanced Football Analytics Win Probability calculator to figure out how a play affected their ability to convert first downs. (They appear to use a slightly different model from Pro Football Reference.)
Lacy had some good runs in this game, but he was really boom or bust - and aside from his 17-yard scamper, his booms were unimpressive while his busts were catastrophic. Let's take a look.
Eddie Lacy left tackle for no gain (tackle by Nick Fairley). Eddie Lacy fumbles (forced by Nick Fairley) recovered by Don Carey at GNB-40 and returned for 40 yards touchdown
This play happened with 12:13 remaining in the first quarter. Before they ran this play the Packers were 46.6% likely to win the game, but after Lacy spotted the Lions 7 points, their winning percentage (henceforth "WP") plummeted to only 23.7% for a net decrease of 22.9%.
Eddie Lacy for -1 yards safety
This play was only partially Lacy's fault. Mike McCarthy should get the Lion's share of the blame. If you were looking to be absolutely sure of giving up a safety you couldn't have called a better play. You made a rookie tight end (Richard Rodgers) responsible for blocking a strong defensive end, you ran directly at the strength of your opponent, and the Lions seemed to know what was coming. Plus, both guards looked absolutely lost on the play.
After the safety, the Packer WP dropped from 42.4% to 37% for a decline of 5.4%. This also resulted in the Lions getting the ball back immediately and driving for a field goal, further decreasing the Packer WP to 26.7%, a 15.7% drop from before the safety.
Eddie Lacy right end for -2 yards (tackle by Jason Jones)
This play took place just after the start of the third quarter. Lacy took a very makeable 2nd and short and turned it into a 3rd and medium, eventually resulting in a punt. Before the play their WP was 31.4%, and they were 74% likely to pick up a first down. After the 2-yard loss their odds of picking up the first down fell to just 47% and their WP fell from to 27.7%. Once they were forced to punt it fell further to 22.7%.
Eddie Lacy left tackle for -4 yards (tackle by George Johnson)
This play took place with 7:47 left in the game on 2nd and 1 from the Detroit 16-yard line. Prior to this play the Packer offense had been humming along nicely on this drive, trailing 19-7 and needing two scores to get back into it. The drive began all the way back at the 10-yard line thanks to a Brandon Bostick penalty on the kickoff, but it took only 3 minutes to move into scoring position. From the Detroit 25 Rodgers actually hit Lacy in the passing game for a nice 9-yard gain on first down, but then is all went south. Before the 2nd down play the Packers were hanging on by a thread with a 6.4% WP, but were at least 83% likely to pick up a first down. After the 4-yard loss they fell to 3.3%, and their odds of converting the first down fell to 47%. When they failed on 3rd down they fell to 1.5%, and once the failed to convert on 4th down the game was essentially over.
I am not against the running game in football if the matchup is right. Many defenses have taken measures to get smaller and quicker to defend against passing-based offenses, and the best way to deal with them is to pound the ball on the ground, but Detroit is not that team. The most frustrating thing about the Packers for me is that they really seem to focus on execution above game plan. They try to do what they do well regardless of the opponent. That's a great philosophy in pee-wee ball, but in professional football it is alarming to see a commitment to a balanced attack for its own sake. It is a sign of a lack of creativity and understanding in an offensive coaching staff.