An analytical look at the 2020 San Diego bullpen

Mandatory Credit: Jake Roth-USA TODAY Sports

Spread the love
Credit: USA Today Sports

An in-depth look at the 2020 San Diego Padres’ bullpen. 

Not a lot of things went right for the San Diego Padres in 2019. Even with the signing of Manny Machado and seeing Fernando Tatis Jr. and Chris Paddack make their major league debuts, the team still went 70-92 and finished 36 games behind the Los Angeles Dodgers.

One thing that did work well was the bullpen. As a group, they totaled an fWAR of 5.4 in 619 total innings pitched, suitable for 6th best in the league. Out of the five teams that finished higher, only one (the Boston Red Sox) failed to make the postseason in some capacity.

It’s not just WAR where they succeeded. As a group, San Diego relievers finished 4th overall in FIP (4.00), 2nd in xFIP (4.08), and 1st overall in SIERA (3.81). Even their strikeout-to-walk ratios were excellent, finishing 6th in K/9 (9.77) and 2nd in BB/9 (2.94).

While former pitching coach Darren Balsley and former bullpen coach Doug Bochtler had a hand in this success, those reigns have been passed to newcomers Larry Rothschild and Ben Fritz, who have been trusted to guide the 2020 bullpen throughout the season.

While many of the old guard will be suiting up in a Padres jersey again, some new faces will be arriving in San Diego. It will be up to new manager Jayce Tingler to correctly utilize his relievers during crucial moments in the late innings.

Using a combination of stats from Fangraphs and BaseballSavant, let’s take a look at each projected reliever for the 2020 season and what they bring to the table.

Kirby Yates

2019 Stats: 60.2 IP, 1.19 ERA, 1.30 FIP, 2.25 xFIP, 2.05 SIERA, 3.4 fWAR, 41 saves

After being snubbed for the National League Closer of the Year award, the MLB realized their mistake and named Yates to the inaugural All-MLB Team. Yates’ humble beginnings as a cast-off of the Los Angeles Angels of Anaheim to All-Star closer are well documented, and it has netted nothing but positives for San Diego.

Yates posted career bests in both strikeout rates (41.6 percent) and walk rates (5.4 percent) as his signature split-fingered fastball has been the bane of opposing hitters league-wide. BaseballSavant has Yates’ splitter making batters whiff at a roughly 34 percent clip.

Baseball Savant also has Yates in the top one percent of the league in xSLG (.259), xwOBA (.224), and xwOBACON (.335). That nasty splitter, as seen above, also averaged 37.6 inches of drop on a vertical plane, inflating the Hawaiian’s chase rate to 30.9 percent and his chase contact rate to 54.5 percent.

Yates is an elite closer that San Diego will have to lock up to a contract extension sooner rather than later since he will be a free agent in 2021. For now, Yates will be coming out to Metallica’s Sad but True in the ninth inning as the lockdown closer.

Craig Stammen

2019 stats: 82 IP, 3.29 ERA, 4.12 FIP, 3.85 xFIP, 3.69 SIERA, 0.4 fWAR

Stammen is back in San Diego after signing a two-year, $9 million deal with a club option for a third year. The 35-year-old took a step back from an outstanding 2018 season, but his numbers may have been inflated from an ugly June, which saw him post an 8.25 ERA. That same month saw him give up four consecutive home runs to the Washington Nationals.

Since signing with the Padres on a minor league deal in 2017, Stammen has pitched a total of 241.1 innings in 209 total games, most of them coming in the seventh or eighth inning as a setup man for either Yates or Brad Hand. 2019 was no different, as Stammen appeared in 76 total games as a bridge to Yates.

Stammen is, however, beginning to show his age. While both his walk (4.4 percent) and groundball rates (50.8 percent) were superb in 2019, his strikeout numbers took a sharp decline. Fangraphs tells us that his strikeout rate dropped from 27.8 percent in 2018 to 21.5 percent in 2019, a six percent decrease. Opposing batters also started to swing at more pitches inside the strike zone (66.9 percent) while making more contact in general (89.3 percent contact rate on pitches inside the zone, 79.7 percent contact overall).

So, how does the above information help the soon-to-be 36-year-old? Well, it doesn’t. Opposing teams are starting to get more confident with Stammen on the mound and, if these trends continue, he will continue to see a decrease in strikeout rates.

His true strength going forward will be his ability to limit walks and fetch ground balls. Even though he got fewer swings on pitches outside the zone, he increased the amount of contact made by a full 14 percent (53 percent O-Contact in 2018 to 67.3 percent in 2019). This is in line with how Stammen’s exit velocity slightly lowered in 2019 despite all three pitches in his arsenal getting fewer whiffs.

Despite the decreasing amount of strikeouts, Stammen is still an effective veteran arm in the Padres bullpen, who won’t need to be leaned on as much due to new additions to the bullpen. He will start the season in the same role as seasons prior, but don’t be surprised if he cedes that role to a younger arm in the second half of the season.

Drew Pomeranz

2019 stats: 104 IP, 4.85 ERA, 4.59 FIP, 3.88 xFIP, 3.86 SIERA, 0.7 fWAR

Signed to a fresh four-year, $34 million contract, Pomeranz makes his return to San Diego a changed man. Where he was once a well-regarded starting pitcher, the left-hander has changed his tune to that of a relief pitcher.

The differences are jarring. Don’t let the above numbers fool you; Pomeranz excelled in the bullpen. After converting to the pen, Pomeranz collected a 1.88 ERA, 1.92 FIP, and a 1.67 xFIP in 28.2 innings of relief between the San Francisco Giants and Milwaukee Brewers.

His strikeout numbers took a jump as well, going from a 24.9 percent as a starter to a 47.2 percent as a relief pitcher while the walks saw a slight drop from 10.3 percent to 7.6 percent in the bullpen.

His reinvention could be stemmed from increased use of his high spin four-seam fastball. After throwing his fastball 39.7 percent of the time in 2018, Pomeranz upped that usage to 52.3 percent in 2019. It saw a slight rise in velocity at 92.8 MPH with a spin rate of 2436 RPM, which helped increase the pitch’s total swing and miss percent rise to 29.3 percent, an eight percent increase from 2018. Pomeranz even got more batters to swing through the pitch when it was in the zone as his fastball generated a 26.1 percent swing and miss rate when it was in the strike zone.

The 31-year-old complemented his fastball with a sharp 12-6 curveball that generated ground balls at a 63 percent clip. Batters chased at the pitch at a rate of 21.8 percent, and they missed it at a staggering 50.7 percent. Even though it averages 81.2 MPH, the curveball still acts as a valuable part of Pomeranz’ arsenal, especially considering his lowered use of the other three pitches he throws.

However, he still only had 28.2 innings of total relief. Yes, he was a valuable member of the Brewers’ pen, but the sample size was small compared to other relievers. Plus, with new rules regarding bullpen management being implemented in 2020, his status as a LOOGY (Left-handed One-Out Guy) has been thrown out the window.

As it stands, Pomeranz will be slotted in as another late-inning reliever to bridge the gap to Yates in a close game.

Pierce Johnson

2019 Stats (Japan): 58.2 IP, 1.38 ERA, 1.26 FIP, 91 K, 13 BB

It is quite tough finding advanced stats for Johnson. Neither Fangraphs or BaseballSavant tracked his progress in Japan, where he spent 2019 pitching with the Hanshin Tigers in the Nippon Professional Baseball League.

The last time he was pitching in the United States, he got clobbered as a member of the Giants, collecting a 5.56 ERA, 4.51 FIP, 5.07 xFIP, and a 4.71 SIERA in 43.2 total innings. Said clobbering led to the decision to take his talents overseas, where he found resounding success.

The 29-year-old paired a mid-90’s fastball with a power curveball and proceeded to dominate. Amongst other set-up men in the NPB’s Pacific League, Johnson finished 2nd in holds with 40 and finished 2nd in total ERA amongst the top 10 set-up men.

The former first-round-pick will now try to join other pitchers like Miles Mikolas and Merrill Kelly in trying to transition that success to the Major Leagues. He signed a healthy two-year, $5 million contract in December, which contains a team option for a third year.


2 thoughts on “An analytical look at the 2020 San Diego bullpen

  1. “suitable for 6th best in the league. Out of the five teams that finished higher, only one (the Boston Red Sox) failed to make the postseason in some capacity.” – VERY Confusing. In the league infers National League. Boston is in the American League. So were the Padres the 6th best in the National League. Or they were 6th best in the Major Leagues, which one?

    1. MLB long ago virtually eliminated the league presidents, combining AL and NL league offices into one under the Commissioner. They just never got around to renaming the two former leagues “conferences”. In this case, “league” is easier to type than “Major League Baseball”. I used MLB, and differentiate the two former leagus as AL and NL.

      The cite of Boston should havee cleared up the confusion, indicating the “6th best” was in the majors, not one of the historical leagues. A quick look at ESPN stats confirms that’s what the author meant.

      When the AFL merged with the NFL, the AFL teams became the American Conference, the NFL teams became the National Conference, and the league became the NFL. Blame the Baseball Commissioner (and owners) for continuing to imagine that the leagues are still separate. The only real difference is the DH – even the formerly separate umpires now work both the NL and AL.

Leave a Reply

Your email address will not be published. Required fields are marked *