There’s only one slight problem here for the Dodgers. I’m not sure he’ll live up to that $8 million-ish a year. Why? To be honest, $8 million a year for a quality set-up man is reasonable - after all, Jeurys Familia just got $30 million over 3 years to set-up Edwin Diaz in Queens, NY. My problem is the problem he’s long had… he walks too many batters.
Let’s be fair, Kelly has been very, very solid for the Sox since movin to the bullpen full time in 2017. He was a passable back-end starter in 2015, and was nowhere as bad as his 4.82 ERA suggested. In 2016, he split time between the bullpen and starting. As a starter, he had a 8.46 ERA in 22 ⅓ innings with 27 strikeouts and 19 walks. But, as a reliever, he had a 1.02 ERA in 17 ⅔ innings with 21 strikeouts against only 5 walks.
So, in 2017, the Red Sox did what they should have done right away when they acquired Kelly, put him in the bullpen full-time. Yes, originally Kelly only wanted to be a starter - I remember this clearly. But, the Sox finally convinced him that being able to throw his 100-mph at full strength for an inning or two was clearly a better option for him AND the team.
Kelly responded with a 2.79 ERA in 54 games and 58 innings in 2017. He had a good strikeout rate (8.07 K/9), but a questionable walk rate (4.19). His 0.7 fWAR (FanGraphs Wins Above Replacement) that year is decided by his 3.49 FIP, a result of all of those walks not coming back to haunt him. His 1.3 bWAR (Baseball-Reference WAR) which considers his ERA is much sunnier.
Kelly’s 2018 season showed the walks catching up to him a bit, posting a 4.39 ERA in only 65 and ⅔ innings over 73 games. However, his 3.57 FIP showed he was pretty much the same pitcher. So, fWAR rewarded him with an identical 0.7 WAR, while bWAR was less forgiving with a 0.5 WAR mark. The upside is that despite a slightly higher walk rate (4.39 BB/9), he did strike out more batters (9.3 K/9). Kelly was also excellent in the playoffs, including 6 scoreless innings with 10 strikeouts against the Dodgers.
So, is a 0.7 WAR reliever worth $8 million a year? Let’s take a look at his 2019 Steamer Projection: 35 innings in 35 games, with a 3.48 ERA (3.52 FIP) 9.9 K/9 and 3.62 BB/9. As a set-up man, he’s probably going to pitch closer to 65 innings. Still, that performance would be worth a whopping 0.3 WAR. With 1 WAR of player value worth about $8 million on the open market, that would a $3 million a year middle reliever, not an $8 million a year set-up man.
Of course, projections are only projections. The point is that walks have held back Kelly in the past. They haven’t kept him from being a good bullpen piece, certainly. His 98.5 mph average fastball is complemented by a decent curveball and passable slider and changeup. So, the stuff is there for him to be a 1 WAR reliever, certainly.
There’s a good chance that Kelly kicks things into a new gear back home in SoCal. (He’s from Anaheim). This could be an OK deal, even if he simply replicates something between his 2017 and 2018 for three straight years. I’ve always been a Joe Kelly fan and if he can find a way to trim his walks a bit more, the Dodgers may have been right all along. The potential is there, and in any case, Joe Kelly is a rich man and he’s back home.