Denver Broncos quarterback Peyton Manning is one of the greatest quarterbacks in NFL history for a lot of reasons. Much is always made of his ability to dissect defenses and consistently put his offensive skill players in positions to be successful. But another is his ability to consistently lead receivers when they're slanting, slashing, digging and posting.
The single most important skill a quarterback can possess is accuracy. It doesn't matter if he can throw it a mile if he can't throw it 10 yards exactly where he wants it. But the definition of "accurate" is subjectiv, because the statistics we try and use to determine accuracy don't take into account other variables. Simply put, there is no perfect statistic to determine a quarterback's accuracy.
Obviously other variables exist, but a wide receiver's ability to pick up yards after the catch (YAC) can be seen as a way to help determine a quarterback's accuracy.
If a receiver is running a slant and has to reach back and/or behind himself to catch the ball, then he's obviously going to slow down. It's that delay that gives the defense a chance to react. This would lessen or eliminate any yards after the catch.
The skill set of a wide receiver plays a huge role in these numbers, as well. A slant pass thrown to DeSean Jackson would be a little different than one to Riley Cooper. But if the pass is completely behind Jackson and he has to turn his whole body to make the catch, there's a much better chance he's not picking up many extra yards.
Just as completion percentage can't be the only determining statistic for accuracy, even if you're discounting drops and throwaway's, YAC isn't a foolproof determinant either, obviously. But a receiver going up and making a one-handed highlight reel play on a pass thrown high and behind him shouldn't necessarily count as an "accurate" pass for the quarterback.
Here's a look at Peyton Manning doing Peyton Manning things.
The Broncos are in "Ace" personnel with one running back, one tight end and three wide receivers. The play results with an 18-yard completion on 3rd-and-9 to tight end Julius Thomas on the dig route.
The red box displays where the pass was caught. You'll notice that it was caught in front of the first down marker, which normally drives fans banana sandwich when they're watching the game. But sometimes that's what the defense is giving you and it takes an accurate pass from the quarterback for the receiver to be able to turn up the field and pickup the first down.
In the bottom two pictures, No. 3 and No. 4, you can see the three Philadelphia Eagles defenders in pursuit of Thomas. If the pass was a bit off-line and Thomas had to reach back and break his momentum to make the catch, there's a good chance the defenders would have converged and tackled him before the first down.
NFL linebackers and defensive backs close in a hurry, especially in the open field, and the slightest break in momentum from the receiver is enough to eliminate the possibility of a first down.
On the right there's a look at New York Giants quarterback Eli Manning doing the opposite of his brother, which ultimately costs his team yards.
Tight end Bear Pascoe might not be the most nimble player in the open field, and with Luke Kuechly and company closing in on him on 3rd-and-long (as seen in the bottom picture), he obviously wasn't going to pick up the first down.
But if the pass had led him towards the sideline, he would have been able to get his head around and attempt to get past that first defender closing in on him.
Instead, he had to contort his body because of the inaccurate pass and by the time he got his body turned and heading up-field, the defender was already on him.
Manning left yards out on the field on this play.
But he did get credit for a completion, so if you're looking at a box score as a determining factor of accuracy in terms of completion percentage, this particular play made Manning look a little bit better.
But it's obvious this wasn't an accurate pass because it didn't lead the receiver and give him a chance to pick up any additional yards.
What's even worse than leaving a few yards out on the field is leaving a whole lot of yards out there.
This play below is from Minnesota Vikings quarterback Matt Cassel.
All of the Pittsburgh Steelers defenders are inside the yellow circle. This is a simple out route from the wide receiver lined up in the slot at the bottom of the screen.
In the second picture you'll see the ball inside the red circle and also the actual trajectory of the ball (red line) and what should have been the trajectory (black line).
The receiver was forced to jump and turn completely around for the ball as he made the catch in that third picture. He lost all momentum and gave the cornerback, who was a good six or seven yards from him when he jumped to catch the ball, the time to close in on him for just an intermediate gain.
If this pass had been thrown accurately, the receiver is just one move away from a possible touchdown. There is no help over the top help on this play. If he just makes one man miss it's a huge gain for the offense, possibly even a touchdown. Simply put, it's a missed opportunity given the play-call and defensive scheme.
These plays have to drive offensive coordinators crazy because they got exactly what they wanted when they called the play and watched it develop.
But again, that tricky box score will count this as a 10-yard gain and a nice play from the offense. A wide open receiver was thrown an inaccurate pass and despite the catch and yards picked up, this play shouldn't be considered a good play for an NFL-caliber offense.
All three of these plays demonstrate how a quarterback's accuracy can be determined by yards after the catch, or lack thereof. All NFL quarterbacks can make these passes or they wouldn't be starting NFL quarterbacks, but the ability to do it consistently and automatically are what separate the average from good, and the good from great.
Peyton Manning is on a different level in terms of leading receivers and ball placement, as evidenced by both film and the numbers. Having three receivers in the top nine in the NFL in yards after the catch isn't a coincidence.
Manning and the Broncos put so much pressure on defensive backs to make plays on moving targets, because receivers aren't having to slow down or break stride to make the catch. That makes for a very difficult time playing against this offense.
So while the YAC statistic is dependent on many variables, mainly the receivers particular skill set that's catching the pass, there are times where it can be seen as a determinant on a quarterback's accuracy.
Finding a way to calculate yards left out on the field could go a long ways in quantifying accuracy, but that's nearly impossible. So we'll just have to keep watching film instead.