I wonder what the data is like on deadline deals for late-inning relievers. You get them when they are on high, they've probably got some wear on them, and then they disappoint. I'm sure there plenty who don't, but thinking of Robertson the last two years, Kimbrel when he went to the White Sox (which was blamed on him not closing), even Ian Kennedy for us (though I don't think there was any illusions that he was a great closer).
Robertson still helped a lot last year and maybe he still will in Miami too though if they miss the playoffs it won't matter.
Also, Kimbrel has a blown save and 2 losses in the same time frame.