What's clear is that Whittingham and Mendenhall have proven to be the right choices for their schools, amid job descriptions that have changed radically and some management mistakes they've made.
Of the 23 major college coaches who took over programs in the '05 season, five remain in place: Whittingham, Mendenhall, LSU's Les Miles, Oklahoma State's Mike Gundy and South Carolina's Steve Spurrier.
"I've said many times I didn't expect to be here that long," Mendenhall said earlier this month.
"Ten years as a head coach is like 30 years as a coordinator," Whittingham said.
They've thrived, not just survived. Each has experienced a rough start, a glorious stretch in the middle and new challenges, revolving around Utah's moving to the Pac-12 and BYU's becoming independent in 2011.
Whittingham barely made it through his first three seasons. And then he could have left after his fifth year, rejecting Tennessee's offer in January 2010.
Having inherited a program with a 16-game winning streak, Whittingham stood 16-13 in September 2007 after a 27-0 loss at UNLV. Then came a 39-4 run that featured a 13-0 record in '08 with a Sugar Bowl defeat of Alabama, followed by a 20-22 downturn that covers three seasons in the Pac-12.
"The challenge of moving into this league has been tough," said Ute quarterbacks coach Aaron Roderick, "but I think we're doing it the right way and I think we've got a really good team this year."
Whittingham is "the same guy every day," Roderick said. "It's nice knowing when you come to work exactly what you're going to get."
That's one way of describing Whittingham's demanding nature. Roderick once was given the play-calling duties in the middle of a season, then was demoted when Norm Chow was hired as offensive coordinator. Dave Christensen is Utah's sixth play-caller in the six seasons since Andy Ludwig departed.
Christensen's performance could determine Whittingham's future. In recruiting cycles, two years remaining is the minimum contract status for a coach to be considered stable. Ute athletic director Chris Hill probably will award Whittingham an extension or dismiss him in December.
Mendenhall's case is different, because of BYU's recruiting niche. He's asked for contracts of shorter duration than the industry standard, and has seemed unlikely to coach past age 50 (he's 48). Yet he's embracing his move away from defensive responsibilities to have a wider impact on the program.
"I'm excited," he said. "And the position I'm in now as head coach, it almost feels … new. I'm refreshed about that kind of approach."
Mendenhall, who took over BYU's program after three losing seasons, enjoyed a 42-7 run in 2006-09 with two Mountain West championships and three wins over Utah in four meetings. Since then, he's 33-19 with four losses to Utah.
Mendenhall's management style has created some controversy, and so has his outspoken view of his job as an ecclesiastical position. Mendenhall either allowed or encouraged offensive coordinator Robert Anae to depart for Arizona after the 2010 season, then brought him back two years later while replacing the entire offensive staff.
"Bronco is the type of leader and coach that doesn't stay still," said BYU linebackers coach Paul Tidwell. "One of his greatest strengths is he loves to learn and loves to progress. I don't think you'll ever find him being complacent."
The same can be said of Whittingham, who believes he's grown into his position. "Ten years in," he said, "I don't want to say I've seen it all, but I've seen most of it."
firstname.lastname@example.org Kyle Whittingham
Age • 54.
Overall record • 76-39.
Conference records • 35-13 Mountain West, 9-18 Pac-12.
Bowl record • 7-1.
Record vs. BYU • 6-3.
Conference titles • 1.
Note • Bowl and overall records include 2005 Fiesta Bowl as co-head coach.
Five biggest wins
No. 1 • Utah 31, Alabama 17, 2009 Sugar Bowl.
No. 2 • Utah 41, BYU 34 (OT), 2005.
No. 3 • Utah 13, TCU 10, 2008.
No. 4 • Utah 30, Georgia Tech 27, 2011 Sun Bowl.
No. 5 • Utah 44, UCLA 6, 2007. Bronco Mendenhall
Age • 48.
Overall record • 82-34.
Conference record • Mountain West, 39-9.
Bowl record • 6-3.
Record vs. Utah • 3-6.
Conference titles • 2.
Five biggest wins
No. 1 • BYU 14, Oklahoma 13, 2009.
No. 2 • BYU 33, Utah 31, 2006.
No. 3 • BYU 38, Oregon 8, 2006 Las Vegas Bowl.
No. 4 • BYU 40, Texas 21, 2013.
No. 5 • BYU 31, TCU 17, 2006.