The Royals bullpen: what is there to regress to?

Do you remember the last time Kelvin Herrera gave up a home run? Do you remember the date? The team? The batter? What was the outcome of the game? (answer below)

Questions like these permeate discussions about the Royals bullpen. Specifically, the three guys at the back end, who combined for a 0.79 ERA over 91 innings in the second half of 2014, and who struck out nearly eleven batters per nine.

Do you remember when Wade Davis gave up his first extra-base hit last year? (It was on July 31) Did you know he only gave up four earned runs from April 26th through the end of the season? That covers 139  Royals games, of which he appeared in 61. Sixty-one appearances, four earned runs.

This is going to sound like stargazing, but when you are this close to the nova it is hard to look away. The reality is, the Royals are in unprecedented territory when it comes to their bullpen. This is the Tinker to Evers to Chance of baseball relief corps, living history that we are bearing witness to.

Greg Holland has a career ERA of 2.17. He has struck out 384 batters in 278 innings.
Kelvin Herrera has a career ERA of 2.52. He has struck out 213 batters in 217.2 innings.
Wade Davis has a career ERA of 1.61 (as a reliever). He has struck out 208 batters in 156.1 innings.

What does regression even look like for them? Is it going from unprecedented to phenomenal? What does that look like in terms of team impact? Overall record? Is the psychological impact of merely existing enough to deter opposing teams?

#Royals bullpen so far: 19 IP, 7 H, 0 R, 3 BB, 21 SO. That'll work.

— David Schoenfield (@dschoenfield) April 14, 2015

The Royals bullpen has not given up an earned run this season. The Cerberus has already combined for ten scoreless and eleven strikeouts. That will not last. All good things shall come to be and not be. This trio won't be around forever. There is this year and next. Greg Holland is a free agent after 2016, as is Wade Davis. Both will command tens of millions of dollars in free agency. Kelvin Herrera is under team control through the 2018 season. This is only a passing phase. But the timbre and echo of its passing is left open to better minds for divination.

*-Kelvin Herrera last gave up a home run on July 26, 2013 to Conor Gillaspie of the White Sox in a 5-1 Royals win.