by Vince Verhei

There was one shining statistical star of the 2013 NFL season, and it's exactly who you think it is. There were two other news-makers, though, who made history for a variety of wrong reasons, and they may have flown under your radar. In fact, one of the most significant players of the year, from a numbers standpoint, didn't play a single down after Week 5.

Using our core advanced metrics -- DYAR and DVOA -- we've gone through the full-season totals at each position and identified the best and worst quarterbacks, running backs, wide receivers, and tight ends from this past season. There's also a look at which players have had their performance most drastically different from their conventional statistics, as well as those players who have had the biggest improvement or decline in their performance from a year ago.

Our annual disclaimer: Numbers are never perfect. While we certainly believe that our metrics do a better job of analyzing a player's performance than anything else you'll see, there are some things statistics can't account for. We'll point out where the data needs some missing context as warranted. Also, remember that DYAR is a cumulative stat, so players who miss time (like Jay Cutler or Aaron Rodgers) will find it harder to make it to these leaderboards.

(More information on these statistics is available here.)

Quarterbacks

Top 5

1) Peyton Manning, Denver Broncos: 2,460 DYAR (2,490 passing DYAR, -30 rushing DYAR)

2) Philip Rivers, San Diego Chargers: 1,754 DYAR (1,759 passing, -5 rushing)

3) Drew Brees, New Orleans Saints: 1,742 DYAR (1,706 passing, 37 rushing)

4) Matt Ryan, Atlanta Falcons: 1,150 DYAR (1,127 passing, 23 rushing)

5) Nick Foles, Philadelphia Eagles: 1,072 DYAR (1,000 passing, 72 rushing)

Analysis: As Peyton Manning laid waste to the NFL record book, internal discussion at FO focused on whether or not he was going to fall a little short of the historical records for our advanced statistics. And though he didn't crack the all-time top ten in passing DVOA, he was second in passing DYAR behind Tom Brady in 2007. (Manning's 2004 and 2006 seasons are now bumped to third and fourth place.) Manning is dinged somewhat for playing an easy schedule, especially when compared to the other great seasons in FO history. The Broncos faced an average pass defense of 10.3% DVOA, which ranked 30th in the league. Only Alex Smith and Robert Griffin faced easier schedules. When Brady set the DYAR record in 2007, the Patriots faced an average pass defense of 3.1% (13th in the NFL). When Manning himself set the DVOA record in 2004, the Colts faced an average pass defense of 6.4% (18th in the NFL).

Even considering the schedule, however, this was a ridiculous season. Manning was the top quarterback in our tables seven times in 2013, and finished in the top 10 six other times. Despite a handful of poor games late in the year, his average ranking in Quick Reads was between fifth and sixth place, and his median ranking was second place. The best game of any quarterback in 2013 was Peyton Manning against Baltimore in Week 1; the second-best game was Peyton Manning against Dallas in Week 5. In fact, in the top 25 games of the year, Manning's name appears nine times. Drew Brees (five) and Philip Rivers (two) were the only other passers to make the top 25 more than once. It was the best season in one of the best careers we will ever have the pleasure of watching.

Rivers enjoyed a nice bounce-back season. After finishing seventh or better every year from 2008 to 2011, he fell to 22nd last season, which we can clearly label a fluke in hindsight. Brees has finished in the top ten every year since 2003, and in the top five seven times in that span. It was the second-best season for both Rivers and Brees. Matt Ryan's raw numbers were ugly, but he also played a brutal schedule that included 13 games against teams that finished in the top half of the league in pass defense DVOA, and seven games against teams that finished in the top six. He got a boost of 300 DYAR after schedule adjustments; no other quarterback went up by even 200 DYAR. Ryan faced that slate with his top receiver out of the lineup for two-thirds of the season, and still made the top six in DYAR for the fourth straight season. He could be the most underrated quarterback in the league. And then there's Nick Foles, who was brilliant in his ten starts, leading the league in touchdown rate, yards per pass, yards per completion, and NFL quarterback rating. He was well behind Manning in DVOA, though, mainly because he had a much higher sack rate (2.7 percent for Manning, 8.1 percent for Foles).

Bottom 5 (with an asterisk)

1) Brandon Weeden, Cleveland Browns: -429 DYAR (-440 passing DYAR, 11 rushing DYAR)

2) Eli Manning, New York Giants: -380 DYAR (-365 passing, -15 rushing)

3) Kirk Cousins, Washington Redskins: -316 DYAR (-317 passing, 1 rushing)

4) Geno Smith, New York Jets: -302 DYAR (-368 passing, 66 rushing)

5) Terrelle Pryor, Oakland Raiders: -284 DYAR (-388 passing, 103 rushing)

Analysis: Brandon Weeden turned 30 years old in October and is entering the decline phase of his career, which is a very depressing thing to think about. Weeden has now finished below replacement level (well below, actually; he had -291 passing as a rookie) in each of his first two seasons, and the track record for players who have done that is dire indeed. It was also the worst season of Eli Manning's career, and the third time he has led the league in interceptions. (Of course, in one of those seasons, he went on to win the Super Bowl.) Given his track record, it's safe to say that his true talent level isn't THIS bad, but he does turn 33 in January, and another subpar season could raise some ugly questions about his future in New York. If Mike Shanahan's plan in Washington was to showcase Kirk Cousins for trade bait, then it backfired. Cousins' dismal performance did nothing but establish that the problems in Washington run far deeper than the quarterback position. Smith's game against Buffalo in Week 10 was one of the worst we've ever measured, but he improved down the stretch. Over the last four weeks of the season, he was 11th-best in passing DYAR. Pryor's season is a hard one to analyze, partly because he bounced in and out of the lineup, partly because of some very specific playing-time splits. Entering the fourth quarter of Week 17, the Raiders were down 34-0 to Denver and Pryor was below replacement level. Pryor then lit the Broncos up for a pair of garbage-time touchdowns. He had more than 100 DYAR in the last quarter of the last game of the year, long after anyone was paying any meaningful attention. Take those 15 minutes away, and Pryor jumps Smith, Cousins, and Manning for second place behind Weeden in this list. None of that really matters, though. This entire list is faulty due to a minor technicality, and a little common sense will tell you that none of these men was the worst quarterback of 2013.

The Worst Quarterback of 2013

Blaine Gabbert ... wait. No. That won't do. We need a different subhead.

The Worst Quarterback of the DVOA Era

That's better. Blaine Gabbert opened the season as the Jacksonville Jaguars starting quarterback, but he was benched after two interceptions, six sacks, and a 28-2 loss to Kansas City in Week 1. He re-entered the lineup for two more games in Weeks 4 and 5, but after five more interceptions and six more sacks, he injured his hamstring and never saw the field again. That left him with 86 pass attempts and 12 sacks, a total of 98 pass plays that came up just short of the minimum 100 needed to qualify for our season tables and record book.

In that minimal playing time, however, Gabbert produced an awful lot of bad football. He finished with -426 DYAR passing and -8 DYAR rushing, a total of -434 DYAR that would put him ahead of (behind?) Brandon Weeden as the worst quarterback of the year. His final passing DVOA was -83.7%. Only two quarterbacks with at least 98 plays have ever been worse than that: Alex Smith as a rookie on a 2005 49ers team that had even less talent than this year's Jaguars (-88.6%), and Craig Krenzel of the 2004 Chicago Bears. (-85.4%). You know that Smith eventually turned his career around, but Krenzel never played again. (The Bears actually went 3-2 in Krenzel's five starts, and he also won a national championship in college. In other words, Craig Krenzel was Tim Tebow before Tim Tebow was Tim Tebow.)

When you add this to Gabbert's rookie season (-1,010 passing DYAR, the second-worst season we've ever analyzed) and his 2012 campaign (-268 DYAR), you get a total of -1,704 passing DYAR. That sure sounds bad, but can we put into context? Why yes, yes we can. Before this season, Danny Tuccito looked over the worst quarterbacks on record in total DYAR, and found that the only quarterback worse than Gabbert was Ryan Leaf. Well, forget that. Gabbert has fallen deep below the Leaf pile, and stands alone and undisputed as the Worst Quarterback of the DVOA Era. No high-profile bust of the past 25 years -- not Leaf, not JaMarcus Russell, not Akili Smith nor David Carr nor Joey Harrington -- has ever been this bad. Each of those notoriously bad passers looks down at Blaine Gabbert, likely with disdain, or perhaps pity.

One final kick in the teeth to former Jaguars GM Gene Smith: Gabbert was the tenth overall pick of the 2011 NFL draft. The Jaguars traded up to pick him. J.J. Watt was the eleventh pick. Andy Dalton went to Cincinnati 25 picks later, and with the next pick after that, the San Francisco 49ers took Colin Kaepernick. And that is why Gene Smith got fired.

Better Than His Standard Stats Made Him Look: Colin Kaepernick, San Francisco 49ers

We could just as easily have listed Tom Brady or Matt Ryan here. All three of these quarterbacks had to play tough schedules, but Kaepernick is the only passer in the NFL who had to to play the league's top two defenses (Seattle and Arizona) twice each. And among starters, only Philip Rivers had a better DVOA than Kaepernick on third downs.

Worse Than His Standard Stats Made Him Look: Matt Flynn, Raiders/Bills/Packers

Flynn's NFL passer rating was 85.7, which finished 21st out of 48 quarterbacks with at least 100 pass plays. He was just a little bit worst than guys like Cam Newton, Andy Dalton, Tom Brady, Andrew Luck, and a little bit better than Matt Stafford or Carson Palmer. Passer rating, though, does not include sacks, and Flynn was sacked on 10.7 percent of his dropbacks, the worst rate in the league. DVOA does include sacks, and by DVOA Flynn was only better than a few other part-timers: Josh Freeman, Terrelle Pryor, Brandon Weeden, and Kirk Cousins.

If we limit our candidates to players with at least 300 plays, the best option here is probably Alex Smith of Chiefs, who had a passer rating of 89.1, but a DVOA of -5.0%. Smith's schedule was very similar to Peyton Manning's and included some of the worst defenses in the league.

Most Improved: Rivers

Per DVOA, Rivers was a below-average quarterback in 2012, and as we've already discussed, he was one of the very best in 2013. New targets Keenan Allen (eighth among wideouts in receiving DYAR as a rookie) and Danny Woodhead (more on him later) had a lot to do with it.

Biggest Decline: Eli Manning, New York Giants/Tom Brady, New England Patriots.

Technically, Manning's DYAR dropped a little more than Brady's did, but the difference is so slight (only 3 DYAR) and the two have so much history that it only makes sense to list them together. We talked about Manning already. Brady had his worst completion percentage since 2004 and the lowest touchdown rate of his career, while losing more yardage on sacks than he ever had before. Brady finished with 981 passing DYAR, his worst healthy season since 2003 and his first below 1,900 since 2006. He'll also turn 37 before the 2014 season starts. Tick-tock. Tick-tock. Tick-tock.

All 2013 quarterback numbers here.

Running Backs

Top 5

1) LeSean McCoy, Philadelphia Eagles: 478 DYAR (342 rushing DYAR, 136 receiving DYAR)

2) Danny Woodhead, San Diego Chargers: 386 DYAR (104 rushing, 282 receiving)

3) Jamaal Charles, Kansas City Chiefs: 381 DYAR (247 rushing, 134 receiving)

4) Knowshon Moreno, Denver Broncos: 363 DYAR (171 rushing, 192 receiving)

5) DeMarco Murray, Dallas Cowboys: 338 DYAR (299 rushing, 39 receiving)

Analysis: LeSean McCoy, Jamaal Charles, and Knowshon Moreno finished first, third, and fourth in yards from scrimmage, so their presence here needs little explanation. It was the second time in three years McCoy has led the league in rushing DYAR, and the third time in four years that he has ranked in the top four. It was also the third time in four seasons he has finished among the top ten running backs in receiving DYAR. Danny Woodhead only ran the ball 106 times (a career high, actually) for 429 yards, but he added 76 receptions for 605 yards, and finished with one of the ten best receiving DYAR totals for a running back in our database. He also had a stuff rate of just eight percent, best of all runners with at least 100 carries. In four healthy seasons, Charles has never finished worse than 12th in DYAR, but this was just his second season in the top 30 in receiving data. In his fifth season, Moreno went over 1,000 yards rushing for the first time, and topped his previous best receiving total by better than 150 yards. DeMarco Murray led all runners in DVOA, and was second behind McCoy in rushing DYAR.

Bottom 5

1) Ray Rice, Baltimore Ravens: -190 DYAR (-169 rushing DYAR, -21 receiving DYAR)

2) Bernard Pierce, Baltimore Ravens: -159 DYAR (-132 rushing, -27 receiving)

3) Willis McGahee, Cleveland Browns: -136 DYAR (-92 rushing, -44 receiving)

4) Andre Brown, New York Giants: -94 DYAR (-45 rushing, -49 receiving)

5) C.J. Spiller, Buffalo Bills: -81 DYAR (-73 rushing, -8 receiving)

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Analysis: Believe it or not, this is not the first time one team has produced the two least-valuable running backs. The 1992 Patriots (Jon Vaughn and Leonard Russell) and 1996 Giants (Rodney Hampton and Tyrone Wheatley) also pulled it off. The 1999 Saints had two running backs (Ricky Williams and Aaron Craver) in the bottom three, and the 2001 Panthers had three (Nick Goings, Richard Huntley, and Chris Hetherington) in the bottom five.

All five of these runners were among the seven runners with stuff rates higher than 24 percent. Among running backs with at least 200 carries since 1989, Ray Rice had the fifth-worst DYAR, and the second-worst DVOA. Bernard Pierce's DVOA was even worse, though he only had 152 carries. The Browns signed Willis McGahee after trading away Trent Richardson, who had -95 rushing DYAR and 39 receiving DYAR with Indianapolis. Of course, Edwin Baker had 41 DYAR rushing and 24 DYAR receiving for Cleveland in only three games at the end of the year, so the Browns are probably pretty OK with that trade, whoever's running that team right now. Andre Brown managed to make this list despite missing the first half of the season. Correlation is not the same as causation, but the Giants offense played better before he showed up. Spiller can't really blame his struggles on his teammates, because backfield-mate Fred Jackson was among the top 10 running backs in total DYAR and rushing DYAR, and his stuff rate was only 14 percent.

Also, while we're discussing bad running backs: Houston's Ben Tate finished with -116 DYAR receiving, the worst single season for a running back in our database.

Better Than His Standard Stats Made Him Look: Woodhead

Second in total DYAR, 23rd in yards from scrimmage.

Worse Than His Standard Stats Made Him Look: Adrian Peterson, Minnesota Vikings

Second in rushing yards per game, ninth in total yards from scrimmage, but just 46th in total DYAR (40 total, 60 rushing, and -20 receiving). His rushing DVOA was in the negative range, His success rate (44 percent) was 32nd out of 48 running backs with at least 100 carries, and his stuff rate (21 percent) was 30th. As a receiver, he averaged only 4.2 yards per target.

Most Improved: McCoy

McCoy was actually llsted under biggest decline last season. That one, clearly, was the fluke.

Biggest Decline: Peterson

One year ago, Adrian Peterson was the most valuable running back in the league. Things change.

All 2013 running back numbers here.

Wide Receivers

Top 5

1) Demaryius Thomas, Denver Broncos: 428 DYAR

2) Jordy Nelson, Green Bay Packers: 401 DYAR

3) Josh Gordon, Cleveland Browns: 389 DYAR (337 receiving DYAR, 52 rushing DYAR)

4) Anquan Boldin, San Francisco 49ers: 385 DYAR

5) Eric Decker, Denver Broncos: 379 DYAR

Analysis: Demaryius Thomas and Eric Decker were both top-five receivers last year too. It's good to play with Peyton Manning. Jordy Nelson is top-five for the second time in three years, and was 15th in 2012. It's good to play with Aaron Rodgers (when he's healthy.) Josh Gordon led the league with 117.6 receiving yards per game, second-best since 1982, and he did that with Brandon Weeden playing quarterback for half a season. (Although, surprisingly, his numbers were similar with Jason Campbell at quarterback.) Anquan Boldin was supposed to hold the fort for San Francisco until Michael Crabtree returned to health but he goes into the playoffs as the 49ers' top weapon. At the age of 33, he had far and away his best season in both DYAR and DVOA (25.6%).

Bottom 5

1) Greg Little, Cleveland Browns: -171 DYAR

2) Davone Bess, Cleveland Browns: -134 DYAR

3) Ace Sanders, Jacksonville Jaguars: -105 DYAR

4) Santana Moss, Washington Redskins: -105 DYAR

5) Kenny Britt, Tennessee Titans: -102 DYAR

Analysis: This is only the second time two receivers from the same team have finished at the bottom of the DYAR tables. The other was in 2007, when Arnaz Battle and Darrell Jackson pulled it off while with the 49ers. Little finished in the bottom ten all-time in both DYAR and DVOA. In fact, he had the tenth-worst DVOA on record, and Bess was 11th. The numbers for Little and Bess didn't change much whether Brandon Weeden or Jason Campbell were at quarterback, so they can't blame their struggles on one passer or the other. Besides, Josh Gordon didn't have any problems playing with the same quarterbacks. (Bess and Little's advanced numbers may be the best testament to Gordon's greatness this season.) Ace Sanders racked up -66 DYAR in the three games started by Blaine Gabbert, but he was still pretty lousy after Chad Henne took over. It was a similar story for Santana Moss, who had -57 DYAR in the three weeks Kirk Cousins started, but he was below replacement level for Robert Griffin, too. He'll be 35 before next season starts, and may be done. Kenny Britt was ninth in DYAR in 2010, but his career has since been a tangled web of injuries, legal woes, and locker-room strife. He'll be a free agent this year, and he insists the Titans never gave him a fair shake and that he can still be a top receiver. Well, what else is he going to say?

Better Than His Standard Stats Made Him Look: Kenny Stills, New Orleans Saints

Stills only caught 32 passes, but he made them count, leading the league with 20 yards per catch. He had 208 DYAR, 20th in the league. He was also 23rd in catch rate. Most importantly, he led the league in both yards per target and DVOA. In fact, with a DVOA of 41.8% and exactly 50 passes, he meets the qualifications for one of the top ten DVOAs in history.

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Worse Than His Standard Stats Made Him Look: Pierre Garcon, Washington Redskins

First in the league in catches and eight in yards, but of the 90 receivers with at least 50 targets, he was 28th in catch rate, 47th in DYAR, 52nd in yards per target, and 63rd in DVOA.

Most Improved: DeSean Jackson, Philadelphia Eagles

Why, yes, now that you mention it, the Eagles offense has improved greatly this season. Jackson had his best season in 2013, finishing seventh with 350 DYAR when he had never finished better than 20th before. Oddly, Jackson's numbers were much better with Michael Vick at quarterback (177 DYAR in six games) than with Nick Foles (173 DYAR in ten games).

Biggest Decline: Michael Crabtree, San Francisco 49ers

Obviously, missing 11 games didn't help, but even when he has seen the field, Crabtree hasn't been the same player he was in 2012. Most of the receivers who declined severely (Randall Cobb, Sidney Rice, Julio Jones, Brandon Gibson, Brandon Stokley) this season had similar injury issues. If you're looking for someone who played 16 games and still declined this season, your best bet is probably Andre Johnson of the Houston Texans, who went from 415 DYAR last year to 148 this year. He had 44 DYAR in eight games with Matt Schaub at quarterback, and 104 in eight games with Case Keenum.

All 2013 wide receiver numbers here.

Tight Ends

Top 5

1) Jimmy Graham, New Orleans Saints: 233 DYAR

2) Julius Thomas, Denver Broncos: 215 DYAR

3) Vernon Davis, San Francisco 49ers: 198 DYAR

4) Tony Gonzalez, Atlanta Falcons: 135 DYAR

5) Jason Witten, Dallas Cowboys: 134 DYAR

Analysis: I've been charting a lot of New Orleans Saints games this year, and I feel outright dirty listing Graham here under tight ends. He's a wide or slot receiver who only occasionally puts a hand on the turf. Now, he's still a really good receiver, one who led the league in touchdown receptions. This actually wasn't his highest DYAR total ever, but it's the first time he has led all tight ends in this category. Julius Thomas was a forgotten bottom-of-the-roster guy in Denver until Peyton Manning arrived and turned him into the second coming of Ozzie Newsome. Vernon Davis enoyed the best season of his career with a full season of Colin Kaepernick. Tony Gonzalez leaves the game the same way he always played it, as one of its very best players. Amazingly, this is his 13th season among the top five tight ends in receiving DYAR. In his first NFL game, his teammates included Marcus Allen, and his opponents included John Elway and Flipper Anderson. Jason Witten has never led all tight ends in DYAR, but he has now been in the top five in nine of the past ten seasons.

Bottom 5

1) Logan Paulsen, Washington Redskins: -96 DYAR

2) Garrett Graham, Houston Texans: -84 DYAR

3) Jermaine Gresham, Cincinnati Bengals: -49 DYAR

4) Brandon Pettigrew, Detroit Lions: -37 DYAR

5) Tyler Eifert, Cincinnati Bengals: -34 DYAR

Analysis: An undrafted free agent in 2010, Paulsen has been a serviceable backup tight end throughout his career, but put into a regular rotation with Fred Davis and Jordan Reed, he stood out as a weak link. Garrett Graham was the target on 40 incomplete passes, more than any tight end except Jimmy Graham, and unlike Garrett, Jimmy Graham made enough plays to justify those incompletions. Pettigrew was the worst tight end in the league last year, so he has at least made some improvement. And what on earth is going on in Cincinnati? Andy Dalton is a perfectly average starting quarterback these days, so why can't any tight end on the team put up decent numbers? Gresham's woes are at least partially self-inflicted; he led all tight ends with three fumbles.

Better Than His Standard Stats Made Him Look: Ladarius Green, San Diego Chargers

Green caught 17 passes this year, never more than four in a game, but he was seventh among tight ends in DYAR this year. He was a consistent deep threat, averaging 22.1 yards per catch (even better than Stills, though he didn't have enough receptions to qualify for that leaderboard), and that wasn't because of one or two long passes skewing his small sample size -- he topped 20 yards per catch in seven of the nine games in which he caught a pass this year. Nine of his 17 passes gained at least 20 yards. Pierre Garcon led the league with 113 receptions, but only 16 of them gained 20 yards.

Worse Than His Standard Stats Made Him Look: Antonio Gates, San Diego Chargers

Awkward! Gates was fourth among tight ends with 77 receptions, but just 16th with 65 DYAR and 29th in DVOA. He had only four touchdowns, his catch rate and yards per target were pretty mundane, and he averaged 11.3 yards per catch, which ranked 27th at his position.

Most Improved: Brent Celek, Philadelphia Eagles.

OK, I cheated a little bit to keep the Eagles theme going. Really, Julius Thomas is the slam-dunk winner here, and Jimmy Graham was also much better in 2013 than he was in 2012 (which is saying an awful lot). But Brent Celek did go from -31 DYAR last to 89 this season. This is interesting, because his receptions fell from 57 to 32, and his yardage fell from 684 to 502. But his touchdowns jumped from one to six, he averaged 3.7 more yards per catch, and he had a top ten DVOA for the first time since 2008.

Biggest Decline: Rob Gronkowski, New England Patriots

Perhaps you've heard, but things haven't gone as well as usual in Foxborough this season. Gronk was tops in our tight ends list in each of the past two seasons, and even though he missed five games in 2012. He missed nine more games this season, and was a shell of his old self when he did play. His DVOA hit at least 40 percent in each of his first three seasons, but stumbled to 13.0% in 2013. Mind you, that was still 13th at the position. But Gronkowski had hit such stratospheric heights in years past that above-average results seem dismal in comparison.

All 2013 tight end numbers here.