What Happened to Doug Martin?

It was the eighth game of the Buccaneers' 2012 season. Through seven contests, their rookie running back, Doug Martin, had rushed for a more-than-respectable 543 yards and 4 total touchdowns.

But this? He had never done this.

On that early November day, Doug Martin became just the second player in NFL history (Mike Anderson being the other) to rush for 250 yards and 4 touchdowns.

The Muscle Hamster was born.

Martin would end his rookie campaign for the Bucs with 1,454 yards rushing, 11 rushing touchdowns, 49 receptions and 472 receiving yards. He became just the third first-year running back to finish a season with 1,400 yards on the ground, 400 more through the air and double-digit touchdowns. The others? Eric Dickerson and Edgerrin James.

Since that rookie campaign, Martin has watched his yards per carry average drop by a full yard, totaling just 950 yards in 17 games played.

What happened?

Martin's Big Rookie Year

Here at numberFire, we care less about raw statistics versus what you'd see elsewhere around the web. Instead, we use Net Expected Points (NEP) to help judge how well a player performs.

You see, not every yard is created equally. A three-yard gain on 3rd-and-3 is a much better play than a three-yard gain on 3rd-and-15, right? Exactly. And NEP accounts for that, taking each down and distance on a football field and attributing an expected point outcome on a particular drive. If a player does better than expected, he's credited with above-zero expected points. If he fumbles the ball and cries his way to the bench (the crying part is irrelevant to NEP, for the record), he'll be dinged.

To get a better idea about NEP, check out our glossary.

Let's start by taking a look at Martin's Rushing NEP (points added on rushing) totals over his three-year NFL career.

At first glance, these numbers probably don't mean a whole lot. So let me give you some context.

Since 2012, running backs with 100 or more carries have averaged a Rushing NEP per rush of -0.01. Why a negative average, you ask? Because rushing is less effective than passing -- it's easier to increase your NEP, naturally, through the air than it is on the ground.

As you can see from the table above, Martin was much better than average during his rookie year, and dropped to be far below average in Year 2 and 3. We've seen 137 100-plus attempt seasons over the last three years, and Martin's per-rush averages rank him 33rd, 116th and 90th. Clearly, something changed.

Was He Just Never Elite?

Or did it? Another metric we've got at our disposal is what we call Success Rate, which measures the percentage of plays that contribute positively towards a player's NEP. If Martin were to pick up a first down, for instance, then that's a positive play. If he fell four yards behind the line of scrimmage for a loss, it would count against his Success Rate.

In 2012 -- remember, this is his "good" season -- Martin finished with a Success Rate of 40.31%. Since 2000, among all running backs who successfully accumulated 10.00 or more Rushing Net Expected Points in a season with at least 100 carries (a sample of 130 running backs), that Success Rate ranks fifth worst.

Martin, in other words, seemed to be creating points via big plays.

This is something many point to when talking about his rookie year. And it's valid. Among all running backs, Martin ranked third in 20-plus yard runs that season, behind only Adrian Peterson (who, no big deal, rushed for almost 2,100 yards), and CJ Spiller. In 2012, Spiller finished with 25.45 Rushing Net Expected Points, more than double the expected points added by Martin.

To put this another way, taking out Spiller's big runs in 2012 would have still resulted in a high Rushing NEP total. For Martin, that's not quite the case.

Now, Martin was certainly better during his first year than his sophomore and junior ones. His Success Rate over the last two years has equaled 39.06% and 34.81%, respectively, and as shown above, his Net Expected Points totals have suffered, too. But perhaps that NEP decline does indeed have a lot to do with his lack of big plays.

On 261 carries over the last two years, Martin has just four 20-plus yard runs, good for a rate of 1.53%. During his rookie campaign, that rate was more than triple that, coming in at 3.43%.

Yes, this 20-plus yard mark is somewhat arbitrary, but it's still giving us a glimpse to the Doug Martin story -- one that shows us that he may be a running back searching for the home run.

Martin has gotten worse as a running back since his rookie year -- I wouldn't argue that point. Even though his first year was highlighted by 60-yard scampers, he was still positively adding points for his team, and his rate in doing so was still greater than what we've seen over the last two seasons. The reason for this decline could come down to a lot of things -- a lack of true quarterback presence, worse offensive line play, or maybe even injury.

But the question of what happened to Doug Martin may have just as much to do with unreasonable expectations as anything else. We all loved his box score numbers, but we didn't necessarily dig deep enough to realize how fortunate things were for him during his first year in the league.

Maybe nothing's really happened to Doug Martin. Maybe this just is Doug Martin.