Certainly, you have a right to your own opinion. But, from the very beginning of his career, Diaz's stats, performance and accomplishments paint a different picture and, with the exception of Texas, ... he's been stellar everywhere he's been.
Florida State
Diaz began his coaching career at
Florida State. During his stint,
Florida State appeared in
back-to-back BCS National Championship Games.
NC State
The
2005 NC State Wolfpack football team finished
eighth nationally in total defense, sixth in third-down percentage, and twelfth in scoring defense and a shutout win over the
South Florida Bulls in the
2005 Meineke Car Care Bowl. Diaz also
served as special teams coordinator and the kickoff return unit finished fifth nationally, while the punt return team blocked four kicks.
In his first year as safeties coach and special teams coordinator in
2004, NC State's defense finished the year as the top-ranked unit in the country in total defense. The Wolfpack defense also
held national powers Ohio State and Florida State to under 130 yards of total offense during the season. His 2004 special teams at NC State also
had three blocked punts and two returns for touchdowns.
In 2002, his first year as a full-time coach, Diaz helped the Wolfpack to one of their best seasons ever, finishing 11–3 and defeating
Notre Dame in the Gator Bowl. He shared in the play-calling duties, and
NC State ended the year ranked 14th nationally in total defense and 10th in scoring defense. In back-to-back games against Florida State and Notre Dame,
NC State did not allow an offensive touchdown.
Middle Tennessee
In four years under Diaz, the Middle Tennessee defense led its conference in sacks and tackles for loss twice, and finished no lower than third in the league in either category during his tenure. In 2009, the Blue Raiders
finished second nationally in tackles for loss, stopping more than eight and a half plays per game behind the line of scrimmage.
Diaz's defense also ranked sixth nationally in sacks that season, posting nearly three per game.
Overall, Diaz' unit
produced 17 all-conference players during his time there and put up
three of the top four fewest yards allowed averages at Middle Tennessee in its FBS era.
Mississippi State
In 2010 with the
Mississippi State Bulldogs,
Diaz guided a defense that ranked 22nd in the nation in scoring defense (19.9 ppg), 17th in rushing defense (214.9 ypg) and 17th in tackles for loss (7.0 pg). That was a dramatic turnaround for MSU from the
season prior to his arrival. In 2009, the defense finished 71st in scoring defense, 62nd in rushing defense and 89th in TFL.
Mississippi State also finished ranked 13th in red zone defense (.73) and 22nd in turnovers forced (28) nationally this season.
Texas
In 2012, Diaz guided the
Texas Longhorns to the worst defense in school history.
Louisiana Tech
In his lone season as defensive coordinator at Louisiana Tech, the Bulldogs led FBS in turnovers gained (42) with 16 fumble recoveries and 26 interceptions.
Second stint at Mississippi State
Diaz spent the 2015 season with the Bulldogs, where his unit
held opponents to 23.2 points per game and ranked in the nation’s top 10 in red zone defense and tackles for loss.