Partly because of their own success, their jobs have become much more demanding. The standards are higher and so is the level of competition.
From a point early in the 2007 season through '09, Utah and BYU went a combined 57-6 in games not involving each other. Nothing like those results will occur again.
Two more fairly safe predictions: Whittingham (69-30) will never catch Mendenhall (71-28) in overall record and Mendenhall will never match Whittingham's unbeaten season of 2008.
Life simply is not the same for these coaches. The competition is magnifying their mistakes and making their programs less relevant nationally. Utah (3-5) needs a strong finish just to avoid Whittingham's first losing season, while BYU (5-4) is assured of a decent record, but nothing special.
"Football is football, regardless of what conference you're in," Whittingham said Monday, "but we're all aware that the bar has been raised tremendously in virtually every area. And that's a good thing. … As a coach, as a player, you want to compete against the best."
The school is backing Whittingham with a major commitment to facilities, staffing and funding. Yet it may take the Utes quite awhile to win the Pac-12 South title after last season's blown opportunity, amid USC's ineligibility.
The scheme Whittingham originally put in place has produced a genuine Pac-12 defense. Utah's ongoing issue is an offense that ranks No. 113.
Whittingham's record is remarkable, considering he stood 17-13 early in his third season. Coinciding with the move to the Pac-12, Utah is experiencing a similar stretch of mediocrity. Since being ranked No. 6 in advance of Texas Christian's visit in November 2010, the Utes are 13-13. That includes three wins over BYU and a 5-9 mark in Pac-12 play.
BYU is 22-13 the past three seasons, although the Cougars are 21-9 since Mendenhall personally took over the defense. If coordinating that defense were his only job, Mendenhall would be a candidate for national assistant coach of the year awards. His defense ranks No. 4 and has not allowed an offensive touchdown against five of nine opponents. No wonder he describes such involvement as his "sanctuary."
But his job description makes him responsible for an inconsistent offense, in a season tainted by his insistence on using senior quarterback Riley Nelson when he was not healthy enough to play effectively against Utah and Boise State.
How long will these guys coach? Whittingham, who turns 53 in November, has a contract through 2016. Mendenhall is 46. Like Whittingham, he says he won't coach forever, and he backs that up by asking for short-term contracts (his current deal runs through 2013).
Each has turned out to be an excellent choice for his school, all considered. But the opponents they're playing now have created ceilings for their programs that are well below the level of expectations they've created.
Utah's Kyle Whittingham and BYU's Bronco Mendenhall are approaching their 100th games as head coaches. Here's how their records to compare to other coaches at their schools through 100 games:
Coach School Years Record
Ike Armstrong Utah 1925-37 73-23-4
Bronco Mendenhall BYU 2005-12 71-28
Kyle Whittingham Utah 2005-12 69-30*
LaVell Edwards BYU 1972-80 68-31-1
Ron McBride Utah 1990-98 59-41
* Includes the 2005 Fiesta Bowl as "co-head coach"