Scott Kacsmar recently wrote about Robert Griffin III’s struggles on third downs last season. Despite Griffin’s otherworldly rate stats, that was one area where he really struggled in 2012. I thought it would be interesting to take a look at how all quarterbacks fared on “third downs” last season. I put that in quotes because I’m including fourth down data, but don’t want to write third and fourth down throughout this post. Regular readers may recall I did something similar last November, but now we can work with full 2012 season numbers.

To grade third down performance, I included sacks but threw out all rushing data (not for any moral reason, just in the interest of time). The first step in evaluating third down performance is to calculate the league average conversion rate on third downs for each distance. Next, I came up with a best-fit smoothed line based on the data, which is based off the following formula:

Conversion Rate = -0.0001 * Distance^2 – 0.0224 * Distance + 0.5301

Take a look at the table below. For example, there were 309 passes (i.e., pass attempts or sacks — scrambles are not included) and the league-wide conversion rate was 51.1%. Using the best-fit formula, the smoothed rate is 50.8%. There is nothing groundbreaking here — the conversion rates drop as the “to go” number increases, but it helps to quantify what we already know.

To Go Passes First Downs Rate Smoothed Rate 1 309 158 51.1% 50.8% 2 415 208 50.1% 48.5% 3 487 207 42.5% 46.2% 4 512 227 44.3% 43.9% 5 559 226 40.4% 41.6% 6 541 228 42.1% 39.2% 7 521 181 34.7% 36.8% 8 426 143 33.6% 34.5% 9 365 116 31.8% 32% 10 728 220 30.2% 29.6% 11 213 71 33.3% 27.2% 12 153 39 25.5% 24.7% 13 135 24 17.8% 22.2% 14 107 22 20.6% 19.7% 15 143 22 15.4% 17.2% 16 62 5 8.1% 14.6% 17 68 12 17.6% 12% 18 50 3 6% 9.5% 19 53 3 5.7% 6.8% 20 48 3 6.3% 5%



Once we know the expected conversion rate for each distance, it’s easy to grade the quarterbacks. The next table is a bit complicated, so let me just walk you through the best third down quarterback in the league last year. Peyton Manning had 176 third down pass plays in 2012. On average, those third down passes came with 8.00 yards to go, and a league-average quarterback would have been expected to convert 37.7% of those third downs (based on the above chart). That translates to 66.3 Expected 1st Down Conversions by Manning (176 * 37.7%). Instead, Manning actually converted 83 first downs, for a 47.2% 1st Down conversion rate. That gives him 16.7 1st Downs over Expectation (i.e., 83 – 66.3), and he had a 9.5% higher rate (47.2-37.7) than the league average quarterback would have given the same situations. That 9.5% number is what the table is sorted by, each quarterback’s per-attempt differential over expectation. The last column is each quarterback’s Net Yards per Attempt on third downs.

There’s probably little predictive data to this, but that doesn’t mean it’s not interesting to examine. No quarterback produced fewer first downs relative to expectation than Andy Dalton (-14.0). Matthew Stafford, who is quickly becoming a very polarizing quarterback, slotted between Manning and Tom Brady in first downs above expectation. Tony Romo, another quarterback/Bullseye, was pretty “clutch” on third downs, too.

As for last year’s rookies, Griffin lagged way behind Andrew Luck in this metric (Russell Wilson, of course, continues to be the man). If you’re looking for a criticism of Griffin’s game, it may be that he struggles to beat the defense in obvious passing situations. According to Football Outsiders, Washington’s offense ranked 1st in DVOA on play-action plays, but below league average on all other pass plays. You know that when we’ve gone from “he threw 5 interceptions in a game, no big deal, he’s a rookie” to “you know that rookie star was a slightly below-average passer on non-play action pass plays,” that we’re picking nits. But hey, it’s July.

Previous “Random Perspective On” Articles:

AFC East: Buffalo Bills, Miami Dolphins, New England Patriots, New York Jets

AFC North: Baltimore Ravens, Cincinnati Bengals, Cleveland Browns, Pittsburgh Steelers

AFC South: Houston Texans, Indianapolis Colts, Jacksonville Jaguars, Tennessee Titans

AFC West: Denver Broncos, Kansas City Chiefs, Oakland Raiders, San Diego Chargers

NFC East: Dallas Cowboys, New York Giants, Philadelphia Eagles, Washington Redskins

NFC North: Chicago Bears, Detroit Lions, Green Bay Packers, Minnesota Vikings

NFC South: Atlanta Falcons, Carolina Panthers, New Orleans Saints, Tampa Bay Buccaneers

NFC West: Arizona Cardinals, San Francisco 49ers, Seattle Seahawks, St. Louis Rams