Josh Jacobs of Alabama has had to answer more questions than normal for a player ranked at the top of his position by most draft analysts.

Jacobs was not a bell cow in the Crimson Tide's offense. In fact, he was back in the pack, not the leader of the running game.

Teammate Damien Harris, also a top 5 prospect this year, led the Tide in rushing the last three years. Harris went over the 1,000-yard mark twice and totaled 3,070 yards for his career to 1,491 for Jacobs.

Jacobs was asked in his Combine media interview how he explained to teams why he should be such a highly rated prospect with such a light workload.

"I just let the film speak for itself," Jacobs said. "I didn't have a lot of carries or nothing like that, but if you look at the production I had when I was in the game, it kind of speaks for itself."

There are no absolutes in judging how prospects will perform in the NFL based on where they're drafted, or how they performed in college.

A look back at last year's draft class shows the perils and payoffs inherent in drafting running backs, and in getting undrafted bargains.

The Lions got a payoff when they traded up to take Kerryon Johnson of Auburn in the second round and 43rd overall. Despite missing six games with a knee injury, he rushed for 641 yards and added 231 yards on 32 catches to show that he can be the No. 1 back the Lions have been looking for.

Saquon Barkley of Penn State, drafted second overall by the Giants, lived up to his draft position by producing 2,028 yards from scrimmage – 1,307 rushing, 721 receiving.

Two Georgia backs drafted ahead of Johnson made an impact. Sony Michel rushed for 931 yards for the Super Bowl champion Patriots. Nick Chubb was part of the Browns' revival with 996 yards rushing.

Also in the second round, Derrius Guice of LSU experienced the ultimate peril. He went out for the season with a knee injury in the first preseason game.

And Phillip Lindsay of Colorado proved to be one of the biggest bargains of the draft. He rushed for 1,037 yards for the Broncos after going undrafted.

Th bottom line on running backs: There are no absolutes in predicting which ones will succeed or fail.

On that cheery thought, following is a breakdown of the top running back draft candidates, with one to watch and others, along with the Lions' position breakdown, draft priority and key stat:

Running back draft rating: The weakest offensive position in the draft, but there are always surprises from running backs who were drafted low or not drafted at all.

Lions' running back breakdown: The position is in its best shape in recent seasons. Johnson returns from an injury-shortened rookie season that established him as the lead runner. C.J. Anderson was signed to add depth and production. Zach Zenner finished strong. Theo Riddick presumably retains his role as the third-down receiving specialist.

Lions draft priority: Likely to use one of nine picks to add depth in the rotation.

Key Lions' stat: The running game improved last season from last in the league in rushing yards per game (76.3) in 2017 to 23rd (103.8). The average gain per carry went up from 3.4 to 4.1.

Top 8 running back prospects:

(Note: Workout results are from Combine or Pro Day.)

1. Josh Jacobs, Alabama: 5-10, 220.

Profile: His three-season workload was fairly light – 251 carries, 1,491 yards -- but he moved the chains when he got the ball: 5.9 yards per rush and 11.9 on 48 receptions. High totals were in 2018: 120 carries, 640 yards, 11 TDs. Leisurely mid-4.6 Pro Day 40 time, but still a Round 1 pick.

2. David Montgomery, Iowa State: 5-10, 222.

Profile: Prolific dual-threat Ohio high school QB, rushed for 6,666 career yards, 91 TDs. Recruited as running back, led Cyclones in rushing all three years: 563, 1,146 and 1,216 yards with 24 TDs last two seasons, 4.7 career average, seven 100-plus yard games in 2018. Combine 40 time 4.63.

3. Damien Harris, Alabama: 5-10, 216.

Profile: Prepped behind Heisman Trophy winner Derek Henry in 2015, led Tide in rushing next three seasons with 1,037, 1,000, 876 yards. One of eight backs in Tide history to hit 3,000-yard mark, with 3,070. Career average 6.4 yards per carry, and over 7.0 twice. Solid 4.56 Combine 40 time.

4. Devin Singletary, Florida Atlantic: 5-7, 203.

Profile: Shared the field with eventual Heisman winner Kyler Murray in opener at Oklahoma, rushed for 69 yards, one TD. Three-year player, 4,299 career yards with seasons of 1,021, 1,921, 1,358 and 66 TDs -- 32 in 2017. Only six receptions in 2018. Disappointing 4.66 Combine 40.

5. Miles Sanders, Penn State: 5-10, 211.

Profile: Didn't just emerge from Saquon Barkley's shadow in 2018. Rocketed away after two understudy seasons: 1,274 yards rushing, nine TDs, 5.8 yards per carry and three games over 150 yds, topped by 200 vs Illinois. Nailed Combine with 4.49 40. No surprise if he goes higher.

6. Darrell Henderson, Memphis: 5-8, 208.

Profile: Playmaker deluxe. Not much not to like about the three-year player, including Combine results: 4.49 40, 22 bench press reps, 10-1 broad jump. Took talent to field with breakout, and breakaway, 2018: 1,909 yards rushing, 8.9 per carry, 22 TD; 19 catches, 295 yards, 15.5 average.

7. Dexter Williams, Notre Dame: 5-11, 212.

Profile: Showed speed at Combine: 4.57 40, quick in agility drills. It was a slow climb to get playing time. Only 99 carries first three years combined, broke out in 2018: 996 yards rushing, 12 TD, 6.3 yards per carry. Stepped into starting role and produced. Sure-handed ball security.

8. Justice Hill, Oklahoma State: 5-10, 198.

Profile: Quick and strong – 4.40 40, 21 reps in bench press, 40-inch vertical jump. Set school freshman rushing record with 1,142 yards in 2016. Took it up a notch to 1,467 and 15 TD as Big12 rushing champ in 2017. Lighter load dropped him to 930 yards in 2018 but with 5.9 average.

One to watch: Karan Higdon Michigan: 5-9, 206.

Profile: Steadily earned increased playing time as a four-year player. Had 11 carries for 19 yards as a freshman and 72 for 425 as a sophomore. With seven starts in 13 games in 2017 produced 994 yards and upped that in 2018 to 1,178 yards. Did not play in the Orange Bowl.

Higdon had eight 100-yard games in 2018, with seven in a row that included 144 in a 21-7 road win over Michigan State. A willing inside runner, he has to develop as a receiver out of the backfield, with only 16 career catches.

Others: L.J. Scott, Michigan State; Rodney Anderson, Oklahoma; Trayveon Williams, Texas A&M; Jalin Moore, Appalachian State; Ryquel Armstead, Temple; Bryce Love, Stanford; Alexander Mattison, Boise State; Benny Snell Jr., Kentucky; Mike Weber, Ohio State; Elijah Holyfield, Georgia; Alex Barnes, Kansas State; Travis Homer, Miami (Fla.).