If there is anything Shaw has shown in his previous hires, it's that he likes to promote from within and strives to have continuity within the program. Choosing Anderson to replace Derek Mason, who left last week to become the head coach at Vanderbilt, fits the mold established with his initial coordinator hires of Pep Hamilton and Mason and last year's promotion of Mike Bloomgren.
The only coordinator hire that came from outside the program in Shaw's tenure was when he named current Raiders defensive coordinator Jason Tarver the co-coordinator with Mason in 2011. Tarver was at Stanford for just that season, in which Mason still served as the play caller.
Shaw and Anderson are the only coaches who remain from Jim Harbaugh's initial staff at Stanford in 2007. Both made the jump with Harbaugh from the University of San Diego.
In all likelihood, this move was at least a year in the making. Anderson reportedly turned down the chance to become the defensive coordinator at South Florida a year ago under Willie Taggart, another former Harbaugh staff member, to remain at Stanford. It was clear then that Mason would land a head-coaching gig sooner rather than later, which makes it reasonable to assume Shaw and Anderson discussed the possibility that he'd be the eventual replacement.
That's roughly how it played out when Bloomgren was elevated from offensive line coach/run game coordinator when Hamilton took the offensive coordinator job with the Colts. In fact, Shaw and Bloomgren discussed the potential for that to eventually happen before he hired him in 2011.
With Anderson's promotion official, Stanford still has three spots to fill on its staff.
In addition to Mason, Shaw needs to replace Mike Sanford, who left to become Boise State's offensive coordinator, and inside linebackers coach David Kotulski, who will serve as Mason's defensive coordinator at Vanderbilt.
Tavita Pritchard shifted from running backs coach to quarterbacks coach immediately after Sanford left, which means the Cardinal is currently without coaches for its running backs, inside linebackers, defensive backs and does not have an official recruiting coordinator.