Both have been HC since 2005 (plus one game in 2004 for KW after Meyer left).

They have remarkably similar records — which is why it's baffling that people seem to rate KW higher. Because he didn't live in OU's shadow, presumably. Regardless, I don't see how any ranking of coaches could put any other coach between them.

Head to head should help settle which is better.

Whittingham

165-79 (.676) overall; 101-60 conference
Bowl record: 10-6 (11-6 if you count 2004)
3 conference championships
3 additional divisional titles
3 BCS/NY6 bowls (1 win: 2008)
7 10-win seasons
8 AP Top 25 finishes

Gundy

169-79 overall (.679) overall; 102-63 conference
Bowl record: 12-6
1 conference championship
3 additional divisional titles
3 BCS/NY6 bowls (2 wins: 2011 and 2021)
8 10-win seasons
10 AP Top 25 finishes

KW did have to make the transition from G5 to P5 — but that gave him a huge recruiting advantage over his main rival. Gundy never had any similar edge over his rival, which was the premier team in its conference and in his state the whole time he was coach (I believe OU won the B12 11 times since Gundy took over — Utah has never had to deal with a similar program blocking the top spot), or being the clear second fiddle for in-state recruiting.