Recruiting reporter Erik McKinney picks a Pac-12 signing day winner and explains how USC closed well, even outside its traditional footprint. (2:18)

STANFORD, Calif. -- This was projected to be a vital recruiting cycle for David Shaw's program long before it began in earnest, simply because the Cardinal were scheduled to see more than 20 scholarship spots open up.

After Austin Hooper, Barry Sanders and Graham Shuler all decided to forego their remaining eligibility on the Farm (either to declare for the NFL draft, to transfer or to retire), 2016 recruiting loomed even larger: Three more scholarships became available, meaning Stanford had about 25 open ones to fill.

Missing the mark on a class of this size can have disastrous ramifications.

But if rankings and prospect evaluations hold any weight, the Cardinal can exhale for now. Shaw's program registered what was its most decorated recruiting effort since the big-time success of 2012. Stanford inked 25 players this national signing day, amassing a haul that includes six ESPN 300 prospects, as well as nine four-star and 14 three-star players.

The Stanford secondary received a boost with the addition of ESPN 300 cornerback Treyjohn Butler. Tom Hauck for Student Sports

ESPN's final ranking has the 2016 Cardinal recruiting class pegged at No. 13 nationally, behind only USC -- No. 11 -- in the Pac-12 conference. That No. 13 matches Stanford's finish in 2012 for the highest in the Jim Harbaugh-David Shaw era, which began in 2007. The 25-player class is the Cardinal's largest in that span, exceeding the previous high of 22 signees.

Whether this haul matches these superlative numbers with quality play on the field remains to be seen. That 2012 class already has been to three Rose Bowls in four years, so a high bar has been set. The initial success of this 2016 Stanford group may be evaluated by how quickly it can alleviate positions of need -- because the Cardinal do have some glaring openings moving forward.

A seeming lack of depth along the defensive line, where stalwarts Brennan Scarlett and Aziz Shittu have both exhausted their eligibility, may be the most apparent concern. For the first time since 2012, Stanford's 2016 class features four defensive linemen: ESPN 300 prospect Mike Williams, Jovan Swann, Thomas Schaffer and Bo Peek. Two of those players already weigh about 300 pounds.

"That's a special group," Shaw said. "Our new freshmen are bigger than the seniors who just left us."

Though he's not up at 300 pounds yet, Schaffer checks in at 6-foot-7. He's the first FBS player from Austria and is expected to bring a uniquely intimidating presence.

"You're gonna see him, but you're gonna hear Arnold Schwarzenegger," Shaw laughed.

Stanford is also looking to fortify its linebacking corps (Pac-12 tackle leader Blake Martinez and senior Kevin Anderson have departed that group), its offensive line (three starters are gone) and a wide receiver unit that lost big target Devon Cajuste.

The 2016 class offers potential answers at all three areas of concern.

Curtis Anderson is the nation's 14th-ranked outside linebacker.

Five offensive linemen, including ESPN 300 prospect Clark Yarbrough and 6-foot-7 left tackle Devery Hamilton, replenish the front's depth.

Pac-12 Signing Day Grades Pac-12 team-by-team grades: A strong finish by USC on signing day left the Trojans as the highest-ranked Pac-12 team, followed closely by Stanford and UCLA.

Donald Stewart, Paxton Segina and Simi Fehoko form a trio of incoming receivers who all measure 6-foot-3 or taller, so Stanford hopes it's covered in that department (the roster already features 6-foot-4 receiver J.J. Arcega-Whiteside).

Stanford's secondary received a pair of late boosts with the flips of former Texas commit Obi Eboh and former Penn State pledge Andrew Pryts. Those two players complement ESPN 300 cornerback Treyjohn Butler, rounding out a unit that has seen tremendous success on the recruiting trail ever since defensive backs coach Duane Akina took over two seasons ago.

The most touted member of the Cardinal's recruiting class likely won't contribute next year. That's quarterback K.J. Costello, the nation's No. 2-rated pocket passer. Shaw called Costello "our quarterback of the future," but hinted that he would likely redshirt while Keller Chryst and Ryan Burns competed to succeed Kevin Hogan under center.

Once Stanford does reach the Costello era, he'll likely be throwing to Kaden Smith, the No. 2-ranked tight end prospect in the nation and another anchor of this 2016 Cardinal class.

Stanford signed Jet Toner, a Hawaii specialist who can punt and kick. The Cardinal also took the rather rare action of recruiting a long snapper, San Antonio's Richard McNitzky, to scholarship.

Bailey McElwain, the fullback/linebacker who many expected to be Stanford’s 26th signee, told ESPN that he is deferring his enrollment. He remains committed to the Cardinal but will not join the program until after this season at the earliest.

There are also some interesting family connections in this Stanford group. Stewart is the cousin of NFL Hall of Famer Emmitt Smith and professional boxer Roy Jones Jr., while running back Trevor Speights is the cousin of Golden State Warriors player Marreese Speights.

"We have some guys with some interesting facts about them," Shaw said. "It will be really nice throughout the years to hear all of their stories. These guys do all these cool things. But that's what Stanford is about. It's about guys who are well-rounded even outside of football."