Summer vacation keeps on chugging along for the Browns, but we're spending the weeks ahead of training camp preparing for endless sun rays and seas of brown and orange-clad fans as far as the eye can see through our much-needed sunglasses. Can you feel us wishing good weather into existence in Berea? Us neither (don't jinx it). 

While we wait for the players to return and the ball boys to roll out the pigskins, we're previewing training camp by looking at each position. Today's group: running backs.

THE RUNNING BACKS

Nick Chubb
Kareem Hunt
Duke Johnson
Dontrell Hilliard
D'Ernest Johnson
Trayone Gray

What we know: This is a loaded position group, and also one headed by a player (Chubb) who had to wait for his turn before exploding onto the scene last season. Perhaps that's the best way to look at this situation: Some of these guys will have to be OK with waiting for their turns. First to hurry up and wait is Hunt, who will miss the first eight games of the season due to a suspension handed down by the NFL. That will shift more of the responsibility on the capable shoulders of Chubb, who enjoyed success that first preceded and then propelled the offense's second-half turnaround in 2018. It should also open the door for more touches for Duke Johnson and potentially Hilliard, too. We also know that on paper, this might be the best group of running backs in the NFL. Hunt looks every bit the player he was before the Chiefs released him late in 2018. Chubb elevated himself as a legitimate candidate to become an NFL feature back. Johnson offers threats in both the running and passing games. And Hilliard has had an excellent offseason. All things are pointing up at this position

What we don't know: When Johnson took his rumored displeasure public during minicamp, it caused some uncertainty related to the position group's depth. What we don't know is what happens next, but we do know that as long as he is here, he'll have an important role in the offense. The latter part came straight from the mouth of head coach Freddie Kitchens … We also don't know how the return man game will shake out, and that's being mentioned here because that could create a fourth spot for a running back if he also wins the returner job. Hilliard and D'Ernest Johnson have each seen reps in the return game, and as we mentioned earlier, Hilliard has a lot of momentum in his favor. Will he win the return job and solidify his chances of making the team?

X-Factor: Hunt, and it's not even close. We know we'll get steady, no-nonsense play from Chubb, and we know that Johnson can make an impact when given opportunities. But the player who might be A) one of the best players on the team, regardless of position and B) the key difference between existing and contending for a conference title is Hunt because of the potential he brings to the table. Even in shorts and helmets, it's clear to the naked eye that Hunt is a special player who could become the Browns' best weapon not wearing No. 13. Should he return from suspension in such form (his play in minicamp suggested that won't be an issue), he stands to lift the Browns into the upper echelon of the NFL with half of a season to play.

The biggest number: 2, as in second down. While the vast majority of NFL teams ran most frequently on first down (and thus gained the most yards per carry), the Browns' dedication to the run produced a 4.9 yards-per-carry average on second down that was a full half of a yard better than the league average in 2018. The Browns scored six times on the ground on second down in 2018, with Chubb accounting for three of those rushing scores. Two of his longest runs of the season -- the 92-yard scamper against Atlanta and the 41-yard burst against Oakland -- were among those scores, which each came on second down. This wasn't a product of excess reliance on the run on second down, as the Browns had just nine attempts more than the league average for the season, but an ability to execute more effectively when a run was less certain. This also helps explain Cleveland's ability to find success in the play-action pass in the latter half of the season, bringing balance to the offense with below-average pass attempts on second down and above-average attempts on third down, with the latter likely a cause of reaching third down more often thanks to running more often on second down. Why does all of this matter? The Browns are equipped with three (or maybe even four, thanks to Chubb's offseason work) running backs who can attack in both areas, making them less predictable based on personnel and more dangerous as an offense. And we haven't even mentioned who's lining up out wide.

Says it all: "The biggest thing Nick has to do is perhaps we just got to catch more balls. At Georgia, they didn't throw him a whole lot of balls but he's working hard every day. If we didn't have so much talent here, I think Nick could be a guy that can have 1,000 yards rushing and 1,000 yards receiving. He's that good, plus I think the offensive system is that good, especially with Baker being able to dump the ball down if we don't have a throw downfield. He can definitely do that. He's a 1,000-yard rushing and receiving guy. Will that happen? I don't know because we've got a lot of talent but he is talented enough to do that." -- Browns running backs coach Stump Mitchell

How many were kept on the initial 53-man roster last year?: 3