Tom Hayes was the other defensive coordinator on this list to work under Bill Snyder. Hayes coached four seasons in the last decade for 2010-2017 and he had two solid season, but the other two were pretty rough.
His two best seasons were in 2014 and 2016 when his defense allowed an average of 369.3 total yards which is great in 2014 and 388.5 total yards in 2016.
However, in the two seasons where the Wildcats' defense struggled in 2015 and 2017, Kansas State allowed 452.2 total yards in 2015 and 426.8 total yards in 2017. It was the pass defense that struggled in Hayes's scheme and in 2017 it was probably the reason Hayes was not brought back because his unit allowed an average 309.1 passing yards to opposing offenses.