How much can Bucs upgrade from Doug Martin in 2018?

As we've tried to convey how much Doug Martin struggled in the past two years with the Bucs, the best stat we'd found was that across the NFL, over the past four seasons, only twice has a player had 125 carries or more in a season and still averaged fewer than 3.0 yards per carry. Those two instances? Doug Martin in 2016 and Doug Martin in 2017.

Warren Sharp tweeted out another one Wednesday morning, pointing out that of the 40 NFL backs who had 200-plus carries over the last two seasons, Martin ranks 40th in yards per carry, 40th in lowest percentage of runs that gain 3 yards or less, and 40th in percentage of runs that gained 5 or more yards. This is why Martin was cut and is now with the Raiders.

In each of the past two seasons, Martin has led the Bucs in carries, but not in yards, and this stands out because in the previous 40 seasons of the Bucs' history, that never happened once. Normally, if you struggle to get yards, other people get the carries, much sooner than the Bucs chose to do so.

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Across the NFL, the Bucs have done that twice in the past two years; the other 31 teams have done it a combined three times. In all those cases, the guy who did lead the team in carries is no longer with the team — see Miami's Jay Ajayi, Tennessee's DeMarco Murray and Carolina's Jonathan Stewart last year.

We also noticed that other Tampa Bay running backs seemed to fare better than Martin behind the same Bucs offensive line. Martin averaged 2.94 yards per carry, while the Bucs as a whole averaged 3.71 yards per carry. We went through all 32 teams, comparing the team rushing average with the average of the player who had the most carries.

It's not hugely telling either way. Only two teams had a larger gap between their top ballcarrier and their team average — the Panthers averaged 4.29 yards, while Stewart (again, now gone) averaged just 3.43; the Packers averaged 4.47 yards, while Jamaal Williams averaged 3.63. The Bucs had the next-biggest gap at 0.77 yards per carry.

In each of the last two years, Martin has averaged a full yard less per carry than the back who ultimately outgained him on fewer carries. Last year, Peyton Barber got 3.9 yards per carry, and in 2016, Jacquizz Rodgers got 4.3, each running behind the same offensive lines that Martin did.

This average-gap stat doesn't point to success or failure. A mobile QB can raise a team's yards per carry quite a bit, as with Carolina's Cam Newton or Seattle's Russell Wilson. Wilson managed to lead the Seahawks in carries and rushing yards last year — he averaged 2.19 yards more per carry than Seattle did as a team.

Dion Lewis averaged 0.76 more yards per carry than the Patriots as a team, and Todd Gurley averaged 0.38 yards more than the Rams as a whole, but in between are two teams (Ravens, Giants) that weren't particularly great.

The Bucs used a second-round pick on USC's Ronald Jones, who comes in with a reputation for big-play ability, having 12 different games in college where he had a run of 40 yards or longer.

We posted a stat from Todd Monken two weeks ago, detailing how the Bucs' longest rushing touchdown of 2017 was … 2 yards. The other seven, all season long, were all 1 yard each. Every other team in the NFL had a rushing touchdown of at least 12 yards.

Jones, by comparison, had 19 rushing touchdowns last year, and that's totally with the benefit of running against Pac-12 defenses all year. His touchdowns included runs of 16, 37, 23, 86, 67 and 64 yards; in all, he rushed for 353 yards on touchdowns last season, and now joins a team that rushed for 9 yards on touchdowns in its 16 games.

Add in the upgrade of Ryan Jensen at center, shifting Ali Marpet to left guard, and there's the potential for a much improved running game, which creates the kind of offensive balance that Dirk Koetter covets. A reliable run game will also help Jameis Winston feel like he doesn't have to do too much, which could lead to fewer turnovers.