For a four-year stretch in Atlanta, there really wasn't much of an argument that Craig Kimbrel was the best closer in baseball. Even if you wanted to throw in another name (Aroldis Chapman, Greg Holland), Kimbrel was always on the short list. After a two-year hiatus as simply being somewhere from good to really good, he's back to being ridiculous. And he might just be better than he was ever before. 

Through 20 outings this season, Kimbrel has worked 20 2/3 innings. He's faced 72 hitters. Of this 72 hitters, he's recorded 40 strikeouts. He's only given up six hits and walked two hitters. That's a 0.39 WHIP while holding opposing hitters to a .087/.125/.159 slash line. 

Here are Kimbrel's rate stats right now versus the average American League reliever: 

ERA

WHIP

K/9

K/BB

Kimbrel

0.87

0.39

17.4

20.00

Average AL reliever

3.90

1.28

9.0

2.53

Even if Kimbrel comes back down to earth some, which he surely will, he's on a historic pace. 

If we set the parameters to having an ERA of 1.50 or less, a WHIP of 1.00 or less and a strikeout rate of at least 13 per nine innings with a 50-inning minimum, there are only eight relief seasons in baseball history. Eric Gagne in 2003, Billy Wagner in 2010, Greg Holland in 2013, Wade Davis in 2014, Dellin Betances in 2014, Andrew Miller last season and ... yep, Kimbrel in both 2012 and 2013. He's the only person to do it twice. 

One could call those parameters cherry-picked or even a bit arbitrary, sure, but it's simply an exercise to illustrate how dominant Kimbrel has been this season, because he's substantially ahead of those figures thus far. It's also a nice illustration of how good Kimbrel has been thus far in his career, given that he's on pace to do it for a third time and no one else has even done it twice. 

It all just got me to thinking that Kimbrel has become wholly underappreciated thanks to two down seasons, but let's take a look at how "down" they actually were. 

In 2015, Kimbrel saved 39 games in 43 chances with a 2.58 ERA (145 ERA+), 1.05 WHIP and 87 strikeouts in 59 1/3 innings. Is that bad? It's not even mediocre. It's just not otherworldly, as we'd grown accustomed to seeing with Kimbrel. 

Last year, Kimbrel saved 31 games in 33 chances with a 3.40 ERA (133 ERA+), 1.09 WHIP and 83 strikeouts in 53 innings. He walked too many guys and the ERA rose, but he also went from Petco Park in the NL to Fenway Park and the AL East. 

One difference this season has been how much more efficient and in control Kimbrel has been. In 2015, he averaged 17 pitches per outing while throwing strikes 63 percent of the time. Last year it was 17.6 pitches per outing while throwing strikes 61 percent of the time. This year he's only needed 14.5 pitches per appearance while hammering the strike zone with 69 percent efficiency. With stuff as good as Kimbrel's near triple-digit average fastball and hard-cutting curve, it's almost not even fair to opposing hitters. 

Also, the general thought process that Kimbrel was struggling surely stemmed from his established standards. From 2011-14, Kimbrel had a 1.51 ERA, 0.88 WHIP and averaged 109 strikeouts a year. He averaged 46 saves in 51 chances in those four seasons for the Braves. 

Again, though, he never really was even mediocre. He was good the last two years. He had just set the bar amazingly high as the best reliever in baseball for four years running. 

It's a bit tough to live up to that standard, even for someone as talented as Kimbrel. This season, he's not only living up to it, he's exceeding it. It's a bit of a throwback cliche, but it appears that Mr. Kimbrel is back and, indeed, better than ever. 

[Thanks, as always, to the indispensable baseball-reference.com for assisting in this research.]