Then again, before you rush to Twitter and demand your team spend whatever it takes to sign the closer who just won a World Series ring, remember that same closer had a 5.91 ERA in nine postseason appearances and often had trouble throwing the ball over the plate consistently.
"Nowhere close to $100 million," one National League scout who has followed Kimbrel's career closely said Thursday about his worth.
For all the focus this week on the Manny Machado free-agency tour and all the talk about whether Machado or Bryce Harper will end up with the biggest mega in his megamillions deal, the most interesting value question on the free-agent market may well concern Kimbrel, the still-unsigned closer who just last week was said by Jayson Stark of The Athletic to be asking for more than that $100 million.
Jon Heyman reported Thursday on Fancred that Kimbrel has since dropped his asking price to $86 million, which would match what Aroldis Chapman got from the New York Yankees when he signed the biggest contract for a closer two winters ago.
"But word is, that is still too rich for the Red Sox," Heyman wrote.
And they know Kimbrel better than anyone, having watched him save 108 games over the last three regular seasons (plus six this October). That doesn't necessarily make them right, but it does make you wonder how willing any team should be to gamble on the next four or five years for a pitcher who is already on the wrong side of 30. Kimbrel isn't yet old, but he does turn 31 in May.
Then again, few pitchers have been as durable and consistent as Kimbrel, who has averaged 65 appearances a year since 2011, his first full year in the big leagues.
No closer has been as consistently good. With a career ERA of 1.91, Kimbrel ranks first all-time among pitchers with at least 500 major league appearances, just ahead of Christy Mathewson and Walter Johnson (who pitched a ton more innings) but also ahead of Kenley Jansen (2.20) and the great Mariano Rivera (2.21).
For the five seasons beginning with his age-31 season, Rivera had 214 saves and a 1.96 ERA. And he did it with one pitch.
"[Kimbrel] has two pitches you can't hit," another National League scout said.
How much is that worth? Plenty, if he can throw them over the plate.
And there you have the issue that makes this whole thing so complicated.
Kimbrel's ERA in 2018 was 2.74, which is high for him but still acceptable for a top closer. He converted 42 of 47 save opportunities, which is basically right at his career average. He allowed fewer baserunners than innings pitched, again pretty close to where he has been in his career.
But there's a reason that first scout was so scared of a contract approaching $100 million. And it wasn't because he has anything against teams spending big for top closers.
"There's more awareness he goes in and out of control," the scout said.
And there you have it. As great as Kimbrel has been and as consistent as his numbers have been, the scary part of giving him a huge contract right now is the concern over whether he'll keep throwing the ball over the plate.
More particularly, the concern is whether he'll keep throwing his fastball over the plate, because Kimbrel is basically a two-pitch pitcher, and if hitters can take the fastball without fear, they're less likely to chase even a very good curveball.
"The No. 1 thing is eight command of his fastball," the second scout said, using the scouting scale in which eight is the absolute tops. "Do people think he has eight command now? I don't."
It's not that easy to show, because Kimbrel's overall strike percentage in 2018 was 62.2, which is just a tick off his 64.6 career average, according to baseball-reference.com. But Kimbrel had stretches in the second half in which his command seemed to desert him—15 walks in his final 19.2 regular-season innings—and that trend continued in the postseason (eight walks in 10.2 innings).
The Red Sox tried to play off his postseason issues as the result of pitch-tipping, suggesting hitters were laying off the curveball out of the zone because they knew it was coming. But whether that was a factor, anyone who watched Kimbrel could see he was struggling to put his fastball where he wanted it.
"Kimbrel is struggling because the strikes he's throwing are down," ESPN's Eduardo Perez told me for a Bleacher Report story in mid-October. "He has to hit the upper quadrants of the strike zone. Once he has to pitch down in the zone, he's done."
Command trouble can sometimes be caused by an injury that subtly prevents a pitcher from repeating his delivery, but the suggestions then and now have been that Kimbrel is healthy. It may just be that he needs to adjust what he's trying to do, with one scout saying he should be willing to dial back a bit on velocity in favor of improving his command.
"If he can do that, he may have another five years at the top level," the scout said.
If he can do that, maybe he really would be worth a $100 million deal. Without knowing whether he can or will, that number still looks far too scary.
Danny Knobler covers Major League Baseball as a national columnist for Bleacher Report.
Follow Danny on Twitter and talk baseball.