"We blew a few winnable games in 2013 & 2016." Every team blows winnable games. EVERY TEAM!!
"A better head coach, given the same support that Fitz was, would have a better record than him over the past 16+ years." Do you realize that this is an ABSOLUTELY MEANINGLESS STATEMENT that can be made for every coach who ever coached, including Bill Belichick and Nick Saban?
"He has blown a lot of games and doesn’t have many signature wins." Fitz has one of the best records in one-score games in college football. NU is actually tied with LSU for #1 in winning percentage in one-score games over the past 16 years at the beginning of the season. Of course, that can be a result of winning close games against poor teams, but usually these close wins were in the B1G.
He's had enough signature wins to attend 10 bowl games, win 5, and win two West division championships, even with a QB coming off of a serious knee injury and Larkin having to hang it up early in the 2018 season. Oh, he got B1G COY that year as well. Well deserved, too! His biggest win against a ranked team at gametime was #4 Iowa (9-0) in 2009, otherwise it's beating final poll #5 Stanford in 2015. His bowl record has been excellent considering we were the underdog in every single game except the 2018 Auburn game where we won easily with a pounding running game at the end.
We have serious problems now that need to be fixed, but I'm not thinking about firing Fitz just yet. That would be silly and would go a long way toward ensuring that we never get a decent coach again. Coach Collins is ripe for firing, though.