Signature Stats Snapshot: Accuracy Percentage

| October 12, 2012

Sometime between Trent Dilfer and the Ravens winning the Super Bowl and now the NFL became utterly dominated by the pass. A team needs to be able to either pass at an elite level or stop the pass at an elite level, and it certainly helps if you can do both. If you expect to win with just a running game and a run-stuffing defense, the odds are not in your favor. Don’t believe me? Since PFF started in 2008 no team has even been to the Super Bowl without finishing in the Top 10 in PFF’s overall passing. Then in the Super Bowl matchups, the team that won has had the higher PFF pass coverage grade every time. So yes, the forward pass is important.

That brings us to PFF’s Signature Stat, Accuracy Percentage. Traditional completion percentage is calculated by taking completions and dividing it by attempts. The problem with this simple formula is that not all incompletions are representative of a quarterback’s accuracy. Drops, throwaways, batted passes, spikes, and plays where the quarterback is hit while throwing are all incompletions that have no bearing on accuracy. So what we here at PFF did was treat those drops like completions and then take away all those other plays from attempts to give a quarterback’s true Accuracy Percentage. The final equation looks like this:

PFF Acc. % = (Completions + Drops) / (Attempts – Throw Aways – Spikes – Batted Passes – Hit As Thrown)

So far through five weeks of the season we have seen some surprising performances. What Robert Griffin III is doing in Washington is unprecedented. He leads the league with a score over seven percentage points higher than any rookie we’ve ever recorded (Matt Ryan’s 74.9% in 2008). He showed incredible accuracy at Baylor, but I’m not sure if anyone expected him to turn Washington’s offense into the eighth-highest scoring team. I don’t think anyone expected Jake Locker to come out in his second year throwing like he has either. His biggest question mark was his accuracy and it’s a shame he got hurt before he could really remove all doubt.

Some quarterbacks have really fallen victim to their receivers dropping balls. Brandon Weeden had a horrid opener, but since then it’s tough to make any summary judgments on him because his receivers have played so poorly. The same can be said for Blaine Gabbert. It’s tough to expect a young quarterback to succeed right away when there are so few offensive weapons around him.

#
Name
Team
Drop backs
Att.
Comp
Drops
TA
BP
SP
HAT
Acc. %
1Robert Griffin IIIWAS166139969322482.0
2Aaron RodgersGB22318913017411180.8
3Alex D. SmithSF1611379410520180.6
4Jake LockerTEN1151066712220379.8
5Matt RyanATL22019913614630179.4
6Matthew StaffordDET18717311416422078.8
7Tom BradyNE19918512414621078.4
8Peyton ManningDEN20919713017431178.2
9Matt SchaubHST1561529713720278.0
10Christian PonderMIN1781581095720177.0

 

Looking at the foot of the list one can see how big an impact accuracy percentage has on an offense. The average points per game of the Top 10 is over five points higher than that of the Bottom 10. Some might not expect Joe Flacco to be this low, as his traditional completion percentage puts him 18th. Unfortunately, Flacco hasn’t evolved into an accurate quarterback so far this year and has really been helped by his receivers’ decreased drop rate. Another guy that hasn’t made the strides his team was hoping for is Mark Sanchez. Sanchez’ sub-50 completion percentage isn’t helped out much here as he is only on target 60% of the time. Jets fans calling for Tim Tebow should know, the only percentage we’ve seen lower than Sanchez’ this year was Tebow’s 2011 Accuracy Percentage.

#
Name
Team
Drop backs
Att.
Comp
Drops
TA
BP
SP
HAT
Acc. %
29Joe FlaccoBLT2001831126410267.0
30Josh FreemanTB130119657530366.7
31Ryan FitzpatrickBUF165152889230066.0
32Andrew LuckIND1991779610334565.4
33Mark SanchezNYJ1691597710451460.0

 

Accuracy Percentage is very difficult for a quarterback to improve on over his career. Although we have seen how it can greatly affect a team’s winning percentage. The Top 10 quarterbacks in terms of Accuracy Percentage have averaged 9.5 wins over the past four seasons. Some of the biggest team turnarounds can be attributed to their quarterbacks being more accurate. The Buccaneers seven-win jump from 2009-2010 was accompanied by a 7.4 percentage point jump from Josh Freeman. The Colts went from 10 wins with Peyton Manning in 2010 to only two wins last year, while their quarterbacks’ Accuracy Percentage dropped 10.3 percentage points. Having an accurate quarterback is a necessity nowadays, and teams can’t hope to compete offensively when their quarterbacks are throwing the ball off target almost twice as much as the top quarterbacks.

 

Follow Mike on Twitter: @PFF_MikeRenner

  • kidfance

    Where can we see the complete list? I’m shocked Cutler isn’t in the bottom 5.

    • That Man

      PFF Premium Obviously.
      And how about Alex Smith? A completely different qb from 2 years ago.

      • Ryan T

        Actually, Alex Smith has been one of the most accurate qbs in the nfl for about 4 years now

  • http://twitter.com/NateWashuta Nate Washuta

    I would be interested in seeing how this compares to yards per attempt. Flacco has been trying a lot of long balls to Torrey Smith, while guys like Alex Smith, Locker, and Stafford have had to largely settle for underneath balls this year.

    • ZWKS

      Agreed. Or maybe create some kind of depth-adjusted accuracy percentage. Looking at the Deep Passing signature statistic page, 8 of the 10 players on the Acc% leaderboard threw deep on less than 10% of their passes, compared with 0 of the bottom 5. Flacco, Sanchez, and Luck are in the top 5 for highest percentage of deep passes.

    • Coder

      Agreed again. For good or bad, I have seen almost every home game Josh Freeman has played in. I agree he is not the most accurate nor does he have the greatest ‘touch’, however, he attempts many more deep passes (now that schiano has unleashed him)

  • Rk

    “Accuracy Percentage is very difficult for a quarterback to improve on over his career.” I’d love to see that backed up with stats. Not because I don’t believe it, I just would love to see the stats.

    • aardvark

      guess Andrew Luck is a bust then.

  • Wgs

    All this shows is how stats can be manipulated
     Jake locker in the top 5 anything besides biggest busts is ridiculous

    • calcio1020

      Biggest busts? His rookie year, he sat and learned behind Hasselbeck, and last year he sat out with an injury for several weeks.. How can you call someone a bust without him being given a chance?