Affirmative: He has been an All-Star in seven of his eight full big-league seasons. He has blown 34 saves in 367 chances. His career WHIP is 0.92, better than Rivera's 1.00. His career strikeout percentage is 41.6, way better than Rivera's 23.0. Kimbrel is 30; Rivera retired at 43. On a list of all-time great relievers, Kimbrel already ranks among the top five.
Negative: Nobody knows those numbers better than the Red Sox, who are in business to stay ahead of the Yankees and win the World Series, goals that sometimes go hand in hand. And yet: They seem willing to let him walk. They made a one-year qualifying offer of $17.9 million, up from the $13 million Kimbrel made last season. According to MLB Trade Rumors, that would have put him above Wade Davis as the highest-salaried reliever ever. Kimbrel declined it.
Affirmative: Because Kimbrel is a free agent, the Braves wouldn't need to raze their farm system to land him. (Owing to the declined qualifying offer, they would lose a draft pick.) They'd just have to spend some money – OK, a lot of money.
Negative: That's the issue. Reports hold that Kimbrel is seeking $100-plus million over six seasons. That's a minimum of $16.6 million per annum. Teams are paying $7-10 million per win, as measured by WAR. Kimbrel's Baseball-Reference WAR average over nine seasons is 2.2, so $16.6 mil isn't utterly outrageous, dollar-wise. It's the six years for a 30-year-old reliever that's the problem. WAR-wise, Kimbrel's 2.3 of 2018 was the fifth-best of his eight full seasons. Going by FIP (fielding independent pitching), last year was his worst. How much longer can he throw this hard? How much of a drain would his contract be come 2022?
Affirmative: Kimbrel came up as a Brave. He was among the very best things about the Braves at the end of the Bobby Cox Era and the beginning of Fredi Gonzalez's tenure. (Though the enduring memory of Fredi G. will be of him leaving the matchless closer in the bullpen as the 2013 NLDS was lost.) Braves fans would love to have him back.
Negative: I'm not a fan of bring-backs. Terry Pendleton's second Braves tour was forgettable. Tom Glavine's ended badly. Granted, Kimbrel is much younger than either of those luminaries when they made their returns, but Take 2, at least in sports, rarely approaches Take 1.
Affirmative: Apart from signing Josh Donaldson for one year at $23 million, the Braves have done nothing this offseason to make themselves better. Signing Kimbrel would make them better.
Negative: How much better? Signing Kimbrel for $100-plus million would fly in the face of advanced analytics – the sabermetric set is adamant that a closer's value is overblown – and the Braves take analytics seriously. A closer works 65 innings. There are cheaper ways of filling those innings. The incumbent Arodys Vizcaino, who missed much of last season with injuries and who has never been an All-Star, blew two of his 16 save chances in 2018. That's an 88.9 percent rate of success. Kimbrel's career save percentage is 90.7. There's a difference, yes, but not a vast difference.
Conclusion: The Braves could use Kimbrel; there's no denying that. In the end, though, this seems a classic example of wants versus needs. Burning massive resources on a reliever should be the last move a gearing-up-to-win-it-all club makes. (Think Aroldis Chapman to the Cubs, Andrew Miller to the Indians, Ken Giles to the Astros.) The Braves are too young to be in champs-or-bust mode, and unspent money shouldn't be dismissed as an asset. Depending on Mike Soroka's shoulder, the Braves might need that money to buy a starting pitcher.
A two-year flier on Kimbrel for $35 million wouldn’t be out of line, but that’s not what he’s seeking. We say again: The quickest way for the Braves to compromise the fruits of their rebuilt is to award big contracts that won’t hold their value. Unless Kimbrel would agree to a shorter deal, I’d say no.