THE X-FACTORS: IOWA'S FIVE MOST IMPORTANT PLAYERS IN 2015

What's the difference between a mediocre season and a good one? For a self-described "developmental" program like Iowa, it's contributions from players stepping into larger roles. Here are five players Iowa needs to get their strongest season out of in 2015.

5. Bo Bower, sophomore WLB

Bower was a starting freshman linebacker who was evidently playing out of position at OLB last year, and that worked out about as well as you'd expect, as Iowa was routinely torched on the edge by faster tailbacks in 2014. The good news is that lots of those running backs have since graduated to the NFL, where they belong, and Bower has been shuffled into the interior, where coaches think he's a more natural fit.

Bower's instincts are generally solid, and if more of his time is spent cleaning up on pursuit in the interior, Iowa's rush defense should be more or less fine. But what set Iowa's last great WLB, Anthony Hitchens, apart was his versatility and coverage skills. Bower still has room to grow here, and the Hawkeyes need him to play fast enough to track RBs and TEs in order to limit third down conversions.

4. Tevaun Smith, senior WR

Iowa's big-play wideout comes into his third year as a starter with 14 starts scattered over the last two seasons, and his career numbers—70 catches, 937 yards, 4 TDs—are surprisingly scant for someone who's been the most NFL-ready receiver Iowa's had since Kahlil Hill. Smith hasn't had more than four catches in a game since Week 2 in 2014 against Ball State. His 596 receiving yards still easily led the team, and he was one of four receivers who led the way with three receiving touchdowns, which should give a proper indication of how decentralized Iowa's passing game was last season.

Iowa can't afford to do that again in 2015. Of the six players (other than Smith) who averaged more than one reception a game in 2014, four have since graduated, another is injured and is already projected to miss multiple games this season (TE Jake Duzey) and the last is Matt VandeBerg. Smith's athleticism and catch skills make him easily the most important target in the passing offense, and if he doesn't get at least eight targets per game, Greg Davis should probably be catapulted into Lake Michigan.

Of course, this means Smith's route-running has to become crisper and his effort needs to be exemplary. Say what you will about DJK and how crazy he drove Ferentz, the man played his ass off on every snap. If Smith can channel that energy, he'll be a star and an easy NFL draft pick. If not... woof.

3. Jaleel Johnson, junior DT

It's fair if your first worry about replacing talent is on the offensive line, but one could argue that the departures of both starting DTs was a bigger loss: Louis Trinca-Pasat looked like the defensive MVP for most of the season, and Carl Davis was equally as essential, easily punishing teams who dared single-teaming him. They leave the door open for Johnson to finally come into his own; Johnson was a four-star recruit out of high school and has looked nigh-unblockable in limited action. He's an athletic 315 pounds and would need to have a pretty lousy fall camp to not start in 2015.

And yet... it feels like we've been waiting on him for a while now, doesn't it? It took a Darian Cooper knee injury to even open the door for Johnson last season, and while Cooper's still... (I'm sorry) re-Cooper-ating (I'm actually not sorry) there's no better opportunity for Johnson to lock the starter spot down. He still needs to fend off fellow hyped recruit Faith Ekakitie, who has been impressing as of late, and who even knows what the other DT spot will look like, as Nathan Bazata and Kyle Terlouw are currently occupying the depth chart.

If Johnson's the monster Iowa expected when he signed four years ago, the complexion of the defense—and opposing play-calling—will change substantially. If, if, if.

2. Boone Myers, sophomore LT

The spring's most jarring mismatch was Drew Ott's thorough and constant dismantling of left tackle Myers, who steps into the massive, Brandon Scherff -sized hole at LT. Under Kirk Ferentz, Iowa has never had a great season without a great offensive line, and it's never had a great season without a great left tackle.

At this point, Ferentz's track record on lineman development has earned him a pretty hefty benefit of the doubt in terms of his player personnel decisions. At the same time, we've still never seen Myers succeed against first-string talent and his ability to protect his signal-caller stands to be essentially the most significant factor in Iowa's success in 2015.

In fact, on that note...

1. C.J. Beathard, junior QB

Above all else, Iowa will be as good as Beathard lets it be in 2015. It was clear at the time (and reinforced at media days) that Iowa wasn't terribly concerned with retaining senior QB Jake Rudock after another middling season in 2014, and there's a level of excitement surrounding Beathard that hasn't been evident since the days of Ricky Stanzi.

There's also no safety net for him, as his primary backup is Tyler Wiegers, a redshirt freshman who certainly looked like a redshirt freshman during spring's open practices. That means there's really no room for error or injury here, and Beathard needs to focus both on staying upright and mistake-free—both challenges for a dual-threat QB with a penchant for chucking it and who'll be working behind a diminished line in 2015.

There's no mystery about the challenges, though, and this program needs a quarterback who's just crazy enough to succeed. If Beathard can be that guy for all 12-15 games Iowa plays this year, the Hawkeyes should always have a fighting chance.