National Signing Day 2014: Which Top Recruiting Classes Are Most Fragile?

College football recruiting can never be predicted, and until the fax machines fire up on national signing day Feb. 5, even the top classes are susceptible to decommitments.

As always, many top recruits will head into the closing stretch of the recruiting season undecided on their futures. With that, many programs are still looking to add to their 2014 recruiting classes.

However, while some teams will mount a strong stretch to wind down the season, others will crumble at the finish.

Click on to see which verbal commits of which programs could cause classes to shatter.

Note: All star ratings based on the 247Sports Composite rankings. The Composite rankings average the rankings of all major recruiting services.

Arizona State

247Sports

Key Commit on the Fence: 4-star ATH Kalen Ballage

When one of a school's top recruits is committed but still undecided, it isn't a good thing.

Arizona State 4-star athlete Kalen Ballage committed on Dec. 11, but took a visit to Nebraska just three days later.

The Peyton, Colo., native—considered a "soft" commit—is still keeping his options open, as reported by Nate Clouse of Rivals.com.

Visits after commitments are never positive signs, and if Ballage spurns ASU, it'll be a major blow to the class currently ranked No. 17 nationally by 247Sports.

Florida

247Sports

Key Commit on the Fence: 5-star RB Dalvin Cook 

A rough season and coaching turmoil is often a perfect formula for top recruits to decommit. Add in an in-state rival that is undefeated and playing for a national title, and the formula is bubbling over.

That's the case with 5-star Florida Gators verbal commit Dalvin Cook.

The Miami Central star has been committed to the Gators since April, but has been looking around as much as any committed recruit in the nation.

Arkansas, Miami (Fla.) and Florida State have all been going after Cook vehemently, but FSU has made the biggest late charge. As seen in the 247Sports crystal ball, there's a great chance he ends up a Seminole.

If Cook heads to Tallahassee, fellow 5-star Ermon Lane could follow him. Lane recently hinted on Twitter that he and Cook will be playing college ball together.

Of course, he didn't specify whether that would happen at UF or FSU. 

If it's FSU, that means the Gators will be without their top two current commits.

Michigan

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Key Commit on the Fence: 5-star ATH Jabrill Peppers

Jabrill Peppers committed early on in the process to Michigan and went to work pulling in other blue-chippers with him.

He tried to persuade 5-star defensive end Da'Shawn Hand to head to Ann Arbor, but the star defensive lineman instead chose Alabama. Now, it is Hand who is trying to flip Peppers to Tuscaloosa, as reported by Adam Friedman of Rivals.com (subscription required), via Nick Baumgardner of MLive.com.

Since then, he went on WTKA-AM radio and affirmed his commitment to the Wolverines, as reported by Baumgardner.

But shortly after that, UM lost its top recruit for the 2015 class, 5-star receiver George Campbell.

UM has been on a cold streak late in the recruiting process, and if Peppers falters, the 2014 Michigan recruiting class will be frostbitten.

Alabama

247Sports

Key Commit on the Fence: 5-star ATH Bo Scarbrough

Alabama stands to gain a lot on national signing day, but the Crimson Tide could also lose some of their top current commits in the process.

Andrew Bone of Rivals.com recently commented that 5-star running back Bo Scarbrough, a longtime UA commit, will keep an eye on the decision of top running back Leonard Fournette, who is considering the Tide. He also added that Ole Miss is still in the mix for Scarbrough.

Scarbrough has also taken a look at Florida State and was recently spotted at a Seminoles practice by the Orlando Sentinel.

The Tide recently lost 4-star safety Laurence "Hootie" Jones, and continuous losses will hurt even the best recruiting classes.

Nick Saban is always known to close well, but given how the actual 2013 season went, this coming recruiting season could bring some surprises.