That record pretty much speaks for itself. Is it something systemic? Bad luck? Both? During the same time period ('15 through the present) Dantonio's record in 1 score games is 12-5 and this record includes his 2016 nightmare season.
What is it about Harbaugh's Michigan teams that they can't seem to win close games, especially if they are big games? The only one of those 5 wins that could qualify as a big game was Wisconsin '16.