Your description screams 'Rafael Soriano v3.0' though. "Here it is, hope you don't throw your back out swinging through it!"
Two posts today, one filed under "The Least of Our Worries" and the other one not. We'll leave you to decide which is which?
There is literature out there which repays nicely a careful re-reading ... To Kill a Mockingbird, 7 Habits of Highly Effective People, Dune, Jeff Sullivan on Edwin Diaz. This August 2016 fangraphs post is chock-full of infotainment. His chart below
Has contact rate (on pitches within the strike zone) up-to-down; Diaz' is lowest. It has "challenge the hitter" left to right; Diaz challenges the most. If you wondered why Diaz "feels" so guaranteed, that's why. Actually you didn't wonder.
This next chart of Jeffy's shows what "percentile" Diaz (as of August) was in, compared to other ML pitchers. For example, the 6th one from the left means that if you lined 100 pitchers up against the wall, according to the number of strikes they threw, Diaz would be 2nd from the end.
And shows what happens when an amusement-park rebel android is given access to its own control pad. (Dr. D will remind you that 100 random ML pitchers include gentlemen like Noah Syndergaard, Hisashi Iwakuma, Aroldis Chapman, David Price, etc.)
And, Sully has five gifs for you. In order, watch for
(1) Simple painted fastball, punch-bunt half swing, Benintendi gropes for the ball and simply cannot see it
(2) Jackie Bradley Jr going to his pepper swing and still being wayyyy behind a challenge fastball
(3) Sandy Leon again using a short-arm little grab for a slider, and getting nowhere near it