Kintzler, Duffey, Pressly, Belisle, Rogers, Hughes, Hildenberger, Gee, Boshers, Busenitz, Breslow, Tonkin, Haley, Turley, Slegers, Wilk, Curtiss, Wimmers, Moya, Perkins, Rucinski, Enns, Melville, Wheeler, Rosario, Tepesch, Heston, and Chris Gimenez. These are the 27 pitchers and one intrepid catcher who made up the Twins relief pitching corps in 2017. By sheer volume alone, the Twins bullpen left a lot to be desired in 2017. There were some bright spots. Brandon Kintzler, who departed to the Nationals via trade, was excellent. Trevor Hildenberger, whose unique approach should make him a staple of the Twins bullpen for the foreseeable future, emerged as a potential bullpen star. The rest of the pen was about as effective as a Matt Asiata run up in middle from inside the five yard line. So where did the Twins stack up against other bullpens when the 2017 season was all said and done?

2017 Bullpen Performance

Just for the sake of comparison, the Yankees, whose relievers threw an arsenal of sonic-boom inducing fastballs that blew the Twins straight out of the wild card game, used 19 relief pitchers last season. The Dodgers, who had an exceptional bullpen, also used 19. While the number of relievers used is hardly an important metric, it is indicative of a contrast in stability in some of MLB’s top bullpens, and that of the Twins.

Minnesota’s bullpen pen logged the tenth most innings of any bullpen in 2017 (looking at you Kyle Gibson and Adalberto Mejia), struck out the fifth fewest hitters (482), and walked the seventh fewest number of hitters (187). Tale as old as time, right? So far, we’ve established that the pen was overworked, didn’t walk many guys, and didn’t strike a lot out either. What about when opposing hitters made contact? The Twins had a significant issue here, giving up the fourth worst Hard% (hard contact percentage) and generating the second worst Soft% (soft contact percentage, significant because there’s a medium contact %) in the league. Essentially, when the Twins gave up contact to opposing hitters, they made a lot of good contact. The Twins bullpen performance in 2017 was actually similar to 2016 (a difference of 0.1 in bullpen WAR), accomplished in a very different way. In short, the pen needed a significant overhaul before the 2018 season. In an organization with a strong offensive lineup and in a market where high level starting pitching is difficult to attract via free agency, the bullpen was the lowest hanging fruit for the Twins front office to attack during free agency.

What was Missing?

So what was the Twins bullpen lacking? One area the Twins pen did improve in 2017 was generating groundballs, improving from 23^rd in MLB in 2016, to 12^th in 2017. This is an area of strength the Twins chose to build upon in 2018, adding Zach Duke and Fernando Rodney to one year deals. In Duke’s last full season before injury, he logged a GB% of 58%, which is elite. Rodney wasn’t too shabby himself, generating GB% of 52% in 2017.

Looking at the most effective bullpens of 2017, an even more integral stat is K/9. This makes a ton of sense, not much can go wrong if you’re striking hitters out on a consistent basis. In 2017, there were 9 teams with a bullpen K/9 of at least 9.5. Between them, these clubs averaged a WAR of 6.5 for their bullpen. The Twins bullpen WAR in 2017 was 2.2, not a disaster, good for 22^nd in MLB. By K/9, the Twins ranked 29^th, with just 7.66 strikeouts per nine innings. Hardly surprising, when you are cycling through nearly 30 relievers over the course of the season. So how do the Twins new additions stack up in generating more strikeouts?

In short, pretty darn well. If you average out the K/9 for Duke, Rodney, and Reed over their last two full seasons of pitching (excluding years significantly impacted by injury), they sit at an average K/9 of 10.00. That’s the kind of strikeout power you want sitting at the back end of your bullpen, particularly if you throw Hildenberger’s 2017 K/9 of 9.43 into the mix too. While past performance isn’t necessarily a good indicator of future results, this is certainly an encouraging trend in remedying a weakness Twins fans have bemoaned, and has impeded the team for years.

Apples and Oranges?

The Twins additions are even more interesting if considered in comparison to another team attempting to ramp up the quality of their bullpen, the Rockies. Colorado spent a Ron Swanson-esque ‘all of the money’ on adding Wade Davis, Jake McGee, and Bryan Shaw this offseason. The Rockies added their relief upgrades for a cost of $30.5 million in 2018. The Twins, by contrast, added Duke, Rodney, and Reed for around $14.65 million in 2018, or around $1.5 million less than it took the Rockies to sign Davis alone for a single year. The average of the Rockies additions K/9 over their last two full seasons pitched is 9.39. While they offer more consistency than a back end containing an ageing Fernando Rodney and Zach Duke returning from Tommy John surgery, the comparison is striking.

There are two more avenues which make this comparison interesting. When looking at the cumulative WAR of the three new relief pitching options for each team over the last two seasons, the Twins trio contributed 6.3 WAR, to the Rockies triumvirates 5.2. While WAR has been put through the ringer in the baseball writing community recently, it is, if nothing else, a useful starting point for a comparison.

Perhaps the Rockies new additions were so much more highly paid because they pitched in higher leverage situations, earning the moniker of ‘super-reliever’ for their respective 2017 teams? WPA (Win Probability Added) examines changes in win probability and reflects how much a player impacted their team’s chances of winning a game. Duke, Rodney and Reed combined for a WPA of 6.08 in their last full season pitched (using 2016 for Duke as 2017 was lost to injury), compared to Davis, McGee, and Shaw’s combined 5.52 in 2017. While the majority of WPA and WAR added for each team was bound up in Reed for the Twins and Davis for the Rockies, comparing the additions in groups of three offers a glimpse at what their cumulative impact on their new teams might be in 2018 in the highest leverage situations each team will face.

This is not to say the Twins signed three better guys than the Rockies, but for a team with their bottom line, they added a significant amount of upside for excellent value, in an area that badly needed to be addressed. As a smaller market team, the Twins don’t have the luxury not to consider short and long term viability when balancing the upside of their free agent signings with the cost it takes to sign them. While the Twins likely won’t have one of the top bullpens in MLB next year, consider the floor significantly raised. If Rodney, Duke, and Reed can maintain a similar level of performance, the Twins will have a much improved pen, cemented by a particularly strong back end that closes the gap between Minnesota and Cleveland.