Hoffman's breakdown is interesting.
43 Appearances - 0 Earned Runs (2 Blown Saves)
7 Appearances - 1 Earned Runs (1 Blown Save)
2 Appearances - 2 Earned Runs (1 Blown Save)
5 Appearances - 3+ Earned Runs (3 Blown Saves - 18 ERs in those 5 appearances)
He's had a couple of bad stretches in the season too.
He's in a bit of one right now in his last two appearances, after he was lights out for the prior 9 games with no earned runs against.
He had the bad stretch in May where he had 11 ERs in three bad appearances against the Angels and Rays where he only went 0.1 innings in each of those games.
I'm sure it's the same story for every closer but if you take out his 4 worst appearances (the three in May, and the game last night) where he gave up 15 ER in 1.1 total innings, his ERA drops from 4.77 to 2.36. So it's really just avoiding the blow up games and trying to identify when those games are happening sooner.
Even with the struggles he's probably a top 10 closer in the MLB this year based on his K/BB ratio, K/9 ratio, and overall WHIP, his blow up games are just really bad.
https://www.espn.com/mlb/stats/closers