MLB tiers: Ranking baseball's best relievers
ESPN PLUS ($ MATERIAL)
My favorite metric when it comes to slotting relief pitchers is win probability added (WPA). According to FanGraphs.com, the top five relievers in that category last season were: Oakland's Blake Treinen, Milwaukee's Jeremy Jeffress, Seattle's Edwin Diaz, Boston's Craig Kimbrel and Milwaukee's Josh Hader. If you followed last season closely, you don't even have to go to the numbers to realize that's a solid listing of the best relievers in baseball.
In most good statistical categories, there is a certain amount of year-to-year consistency. There are always changes, but the leaderboard from one season to the next doesn't look as if you've accidentally subbed in names from another sport. But you know where Treinen -- the reigning WPA leader -- ranked in that metric in 2017? That would be 595th. Jeffress? He was 555th. Even Diaz, who was already established as a premier reliever, ranked just 62nd.
With relievers, you just don't know how the landscape will look from one season to the next.
Building a bullpen is hard, for just this reason. No position group varies as wildly in its performance from one season to the next as relievers. It's not even close. That's why, as much as anything, the best reliever of the current decade -- Craig Kimbrel -- has yet to find a home via free agency.
With that rather large caveat, we conclude our position tiers series with relievers. Squirrelly as they might be, their prominence in baseball has never been greater, in innings, in sheer number of pitchers, in the impact on deciding individual games.
We've reached this place with relief pitching in large part because of analytically driven strategic evolutions over the past 30 years or so. But we've also gotten here because the supply of big-armed relief pitchers has never been greater. That's certainly true in the major leagues, and by all accounts, it's just as true in the minors.
There used to be an adage in baseball that if what you have in the bullpen isn't any better than what you've got on the mound, then you stick with what you've got on the mound. Nearly all of the best arms in baseball were starters, so the goal for every manager was to get as many innings out of his rotation as possible.
Now that's not really a thing. Starters aren't judged so much for their stamina as they are for their pitch efficiency. Can they get through the order twice without burning through too many pitches? Good enough, because there is a crew of flamethrowers ready to come on and finish it off. Managers don't dread going to the bullpen -- they can hardly wait to do it. It's the most fundamental change to the experience of taking in big league baseball over the past decade.
As with the starters, we can take a snapshot of teams' bullpen situations by seeing how many relievers they have in each tier. This is a role-independent evaluation except in this regard: By awarding more points for the better tiers, we can in effect replicate the effect of leverage on how bullpens are set up. The better relievers, if used in an optimal fashion, should have a disproportionate impact on their team's chances to win in a given game. That's what leverage is.
It's not a perfect way to look at it, but it's worth checking out, even if that year-to-year volatility that I mentioned is a giant red flag that these rankings probably will look very different by the end of the 2019 season.
<offer style="box-sizing: border-box;"></offer>
<aside class="inline inline-table" style="box-sizing: border-box; font-family: -apple-system, BlinkMacSystemFont, Roboto, Arial, "Helvetica Neue", Helvetica, sans-serif; height: 979px; border: 1px solid rgb(220, 221, 223); clear: both; margin: 6px 0px 18px; padding: 15px; width: 565px; color: rgb(0, 0, 0); font-size: 16px;">Tier-Based Bullpen Rankings
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Tier I (franchise performers) & Tier II (All-Stars):
Some of them might be really good, but they're still relief pitchers.
Tier III: First-division regulars
Edwin Diaz, New York Mets (R)
Position rank: 1
hWAR: 2.84
In his third big league season, Diaz shook off the inconsistencies of his first two campaigns and became a legit relief ace. In 73⅓ innings, he struck out 124 batters -- a rate of 15.2 per nine innings -- and walked only 17. He improved his first-strike percentage from 55.8 percent to 67.3. When you get behind in the count to Diaz, you've got no chance against his slider. According to StatCast, Diaz's overall .212 xwOBA (expected weighted on-base percentage) was the lowest any pitcher allowed in baseball. The xwOBA on his slider: .163. That's just not fair.
Tier IV: Second-division regulars
Josh Hader, Milwaukee Brewers (L)
Position rank: 2
hWAR: 2.28
Hader won the Trevor Hoffman Award as the National League's top reliever last season, a testament to his dominance, our collective improvement in evaluating relievers, and the brilliance with which Milwaukee deployed its best pitcher. That latter factor was clear during the Brewers' terrific seven-game loss to the Dodgers in the NLCS, when Hader's availability and looming presence seemed to shadow the decision-making of L.A. manager Dave Roberts like a nagging cough. Hader struck out 143 batters last season in 81⅓ innings. He gave up 36 hits.
Andrew Miller, St. Louis Cardinals (L)
Position rank: 3
hWAR: 2.26
Hader usurped Miller's status as baseball's greatest lefty nuclear option. Miller just couldn't get healthy for any stretch of time during his last season for the Indians, spending time on the DL for a strained hamstring, right knee inflammation and a shoulder impingement. The lack of continuity showed in his numbers. Over just 34 innings, his WHIP rose from 0.38 to 1.38 and his ERA ballooned from 1.44 to 4.24. If Miller is healthy this season, St. Louis will have the kind of weapon to negate what division rival Milwaukee has in Hader.
Kenley Jansen, Los Angeles Dodgers (R)
Position rank: 4
hWAR: 2.19
The Dodgers gave Jansen spring training off last season, a statement that isn't as much of an exaggeration as it might seem. He started poorly, struggled with muscle pulls and a recurrence of old heart rhythm problems, and posted the worst season of his career. His 3.01 ERA tells only part of the story. Jansen gave up 13 homers in 71⅔ innings, more than twice the number of long balls he'd ever given up in a season. Too often, Jansen simply didn't know if his cutter would behave as it always had. His xwOBA on the pitch -- long one of the most devastating in baseball -- jumped from .223 to .271. The same number on his slider went from .089 to .240. Early reports from spring training have been encouraging, as spring reports so often are. Jansen has lost 25 pounds and has learned to use tracking data to amp up the spin rate on his pitches.
Blake Treinen, Oakland Athletics (R)
Position rank: 5
hWAR: 2.18
One thing that should have jumped out from the WPA chart used for the illustration above: Treinen was one of baseball's most improved performers in 2018. You can really trace his improvement to 2017, after he was traded to Oakland from Washington in the deal that sent Sean Doolittle and Ryan Madson to the Nationals. According to StatCast, Treinen has relied more on his four-seamer since moving to the A's and last season started throwing a cutter on about one out of every 10 pitches. His xwOBA on those offerings was .144. That's how you lead the majors in WPA.
Aroldis Chapman, New York Yankees (L)
Position rank: 6
hWAR: 2.12
Chapman's max-effort, blinding-speed game will never hold up over any length of time. Sure, it's impressive to see a guy who can come in and light up the radar, but there is more to succeeding on the mound than sheer velocity, especially as a pitcher ages and his stuff begins to diminish. ... OK, you've probably picked up on what I was doing there. Chapman, for lack of a more elegant term, is a freak. He's nine years into a successful career that has consisted of rearing back and blowing hitters away. But last season, some cracks appeared in his facade. Chapman's average four-seam velocity dipped below triple digits for the first time since 2013 and his xwOBA on those pitches rose from .275 to .352. He began to throw his slider more, and to good effect. This season, we might find out if that adjustment will hold up for a few more years of dominance or if hitters will finally start to get their revenge for all those years of whiffs.
Other Tier IV relievers: 7. Corey Knebel, Brewers (2.08 hWAR); 8. Craig Kimbrel, free agent (2.07 hWAR); 9. Felipe Vazquez, Pittsburgh Pirates (1.95 hWAR); 10. David Robertson, Philadelphia Phillies (1.83 hWAR); 11. Brad Hand, Cleveland Indians (1.78 hWAR); 12. Roberto Osuna, Houston Astros(1.70 hWAR); 13. Dellin Betances, Yankees (1.69 hWAR); 14. Zack Britton, Yankees (1.67 hWAR); 15. Sean Doolittle, Washington Nationals (1.64 hWAR); 16. Ken Giles, Toronto Blue Jays (1.61 hWAR); 17. Raisel Iglesias, Cincinnati Reds (1.54 hWAR); 18. Kirby Yates, San Diego Padres (1.53 hWAR)
Kimbrel is a future Hall of Famer and has been so good for so long now that you wonder if whatever he was asking for this winter was just out of whack for what any short reliever can get. That's especially true for a player who is coming off a career-worst 3.13 ERA, lost 2.5 strikeouts per nine innings off his 2017 figure and gave up a career-high seven homers. Then, when the Red Sox were in position to slam the door in the World Series, it was Chris Sale, not Kimbrel, who got the call. None of this is to say that Kimbrel can't be a top-flight reliever for a few more years. It's just to say that the rare certainty he always provided -- his most valuable trait, really -- might no longer be there. Whatever is going on, Kimbrel needs only to look at Greg Holland's 2018 travails as an example of why it's probably better that he get into a camp sooner than later.
As for Doolittle ... that's a heck of a good literary name, don't you think?
op from Tier V (role players):19. Matt Barnes, Boston Red Sox; 20. Brad Peacock, Astros; 21. Alex Colome, Chicago White Sox; 22. Ryne Stanek, Tampa Bay Rays; 23. Jeremy Jeffress, Brewers; 24. Jeurys Familia, New York Mets; 25. Will Smith, Giants; 26. Ryan Pressly, Astros; 27. Cody Allen, Los Angeles Angels; 28. Craig Stammen, Padres; 29. Wade Davis, Rockies; 30. Keone Kela, Pittsburgh Pirates; 31. Chad Green, Yankees; 32. Jose Alvarado, Rays; 33. Taylor Rogers, Minnesota Twins; 34. David Paulino, Blue Jays; 35. Archie Bradley, Arizona Diamondbacks; 36. Jose Leclerc, Texas Rangers; 37. Will Harris, Astros; 38. Seranthony Dominguez, Phillies; 39. Joe Kelly, Dodgers; 40. Matt Strahm, Padres; 41. Chris Devenski, Astros; 42. Scott Alexander, Dodgers; 43. Hector Rondon, Astros; 44. Mychal Givens, Baltimore Orioles; 45. Hector Neris, Phillies; 46. Shane Greene, Detroit Tigers; 47. Seth Lugo, Mets; 48. Tony Watson, San Francisco Giants; 49. Joakim Soria, Athletics; 50. Andrew Kittredge, Rays.
ESPN PLUS ($ MATERIAL)
My favorite metric when it comes to slotting relief pitchers is win probability added (WPA). According to FanGraphs.com, the top five relievers in that category last season were: Oakland's Blake Treinen, Milwaukee's Jeremy Jeffress, Seattle's Edwin Diaz, Boston's Craig Kimbrel and Milwaukee's Josh Hader. If you followed last season closely, you don't even have to go to the numbers to realize that's a solid listing of the best relievers in baseball.
In most good statistical categories, there is a certain amount of year-to-year consistency. There are always changes, but the leaderboard from one season to the next doesn't look as if you've accidentally subbed in names from another sport. But you know where Treinen -- the reigning WPA leader -- ranked in that metric in 2017? That would be 595th. Jeffress? He was 555th. Even Diaz, who was already established as a premier reliever, ranked just 62nd.
With relievers, you just don't know how the landscape will look from one season to the next.
Building a bullpen is hard, for just this reason. No position group varies as wildly in its performance from one season to the next as relievers. It's not even close. That's why, as much as anything, the best reliever of the current decade -- Craig Kimbrel -- has yet to find a home via free agency.
With that rather large caveat, we conclude our position tiers series with relievers. Squirrelly as they might be, their prominence in baseball has never been greater, in innings, in sheer number of pitchers, in the impact on deciding individual games.
We've reached this place with relief pitching in large part because of analytically driven strategic evolutions over the past 30 years or so. But we've also gotten here because the supply of big-armed relief pitchers has never been greater. That's certainly true in the major leagues, and by all accounts, it's just as true in the minors.
There used to be an adage in baseball that if what you have in the bullpen isn't any better than what you've got on the mound, then you stick with what you've got on the mound. Nearly all of the best arms in baseball were starters, so the goal for every manager was to get as many innings out of his rotation as possible.
Now that's not really a thing. Starters aren't judged so much for their stamina as they are for their pitch efficiency. Can they get through the order twice without burning through too many pitches? Good enough, because there is a crew of flamethrowers ready to come on and finish it off. Managers don't dread going to the bullpen -- they can hardly wait to do it. It's the most fundamental change to the experience of taking in big league baseball over the past decade.
As with the starters, we can take a snapshot of teams' bullpen situations by seeing how many relievers they have in each tier. This is a role-independent evaluation except in this regard: By awarding more points for the better tiers, we can in effect replicate the effect of leverage on how bullpens are set up. The better relievers, if used in an optimal fashion, should have a disproportionate impact on their team's chances to win in a given game. That's what leverage is.
It's not a perfect way to look at it, but it's worth checking out, even if that year-to-year volatility that I mentioned is a giant red flag that these rankings probably will look very different by the end of the 2019 season.
<offer style="box-sizing: border-box;"></offer>
<aside class="inline inline-table" style="box-sizing: border-box; font-family: -apple-system, BlinkMacSystemFont, Roboto, Arial, "Helvetica Neue", Helvetica, sans-serif; height: 979px; border: 1px solid rgb(220, 221, 223); clear: both; margin: 6px 0px 18px; padding: 15px; width: 565px; color: rgb(0, 0, 0); font-size: 16px;">Tier-Based Bullpen Rankings
| TEAM | I | II | III | IV | V | VI | PITCHERS | RATING |
|---|---|---|---|---|---|---|---|---|
| Yankees | 0 | 0 | 0 | 3 | 3 | 1 | 7 | 2.29 |
| Phillies | 0 | 0 | 0 | 1 | 4 | 0 | 5 | 2.20 |
| Mets | 0 | 0 | 1 | 0 | 4 | 1 | 6 | 2.17 |
| Astros | 0 | 0 | 0 | 1 | 7 | 0 | 8 | 2.13 |
| Athletics | 0 | 0 | 0 | 1 | 6 | 1 | 8 | 2.00 |
| Brewers | 0 | 0 | 0 | 2 | 4 | 2 | 8 | 2.00 |
| Twins | 0 | 0 | 0 | 0 | 6 | 0 | 6 | 2.00 |
| Indians | 0 | 0 | 0 | 1 | 2 | 1 | 4 | 2.00 |
| Dodgers | 0 | 0 | 0 | 1 | 5 | 2 | 8 | 1.88 |
| Rays | 0 | 0 | 0 | 0 | 7 | 1 | 8 | 1.88 |
| White Sox | 0 | 0 | 0 | 1 | 4 | 2 | 7 | 1.86 |
| Cardinals | 0 | 0 | 0 | 1 | 4 | 2 | 7 | 1.86 |
| Blue Jays | 0 | 0 | 0 | 1 | 3 | 2 | 6 | 1.83 |
| Angels | 0 | 0 | 0 | 0 | 5 | 1 | 6 | 1.83 |
| Padres | 0 | 0 | 0 | 1 | 7 | 3 | 11 | 1.82 |
| Cubs | 0 | 0 | 0 | 0 | 7 | 2 | 9 | 1.78 |
| Pirates | 0 | 0 | 0 | 1 | 3 | 3 | 7 | 1.71 |
| Giants | 0 | 0 | 0 | 0 | 4 | 2 | 6 | 1.67 |
| Braves | 0 | 0 | 0 | 0 | 4 | 2 | 6 | 1.67 |
| Tigers | 0 | 0 | 0 | 0 | 5 | 3 | 8 | 1.63 |
| Nationals | 0 | 0 | 0 | 1 | 3 | 4 | 8 | 1.63 |
| Orioles | 0 | 0 | 0 | 0 | 5 | 3 | 8 | 1.63 |
| Reds | 0 | 0 | 0 | 1 | 3 | 4 | 8 | 1.63 |
| Mariners | 0 | 0 | 0 | 0 | 3 | 2 | 5 | 1.60 |
| Rockies | 0 | 0 | 0 | 0 | 4 | 3 | 7 | 1.57 |
| Rangers | 0 | 0 | 0 | 0 | 4 | 3 | 7 | 1.57 |
| Red Sox | 0 | 0 | 0 | 0 | 4 | 3 | 7 | 1.57 |
| Diamondbacks | 0 | 0 | 0 | 0 | 4 | 3 | 7 | 1.57 |
| free agents | 0 | 0 | 0 | 1 | 3 | 9 | 13 | 1.38 |
| Royals | 0 | 0 | 0 | 0 | 3 | 7 | 10 | 1.30 |
| Marlins | 0 | 0 | 0 | 0 | 2 | 5 | 7 | 1.29 |
| Total | 0 | 0 | 1 | 18 | 132 | 77 | 228 | 1.75 |
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Tier I (franchise performers) & Tier II (All-Stars):
Some of them might be really good, but they're still relief pitchers.
Tier III: First-division regulars
Edwin Diaz, New York Mets (R)
Position rank: 1
hWAR: 2.84
In his third big league season, Diaz shook off the inconsistencies of his first two campaigns and became a legit relief ace. In 73⅓ innings, he struck out 124 batters -- a rate of 15.2 per nine innings -- and walked only 17. He improved his first-strike percentage from 55.8 percent to 67.3. When you get behind in the count to Diaz, you've got no chance against his slider. According to StatCast, Diaz's overall .212 xwOBA (expected weighted on-base percentage) was the lowest any pitcher allowed in baseball. The xwOBA on his slider: .163. That's just not fair.
Tier IV: Second-division regulars
Josh Hader, Milwaukee Brewers (L)
Position rank: 2
hWAR: 2.28
Hader won the Trevor Hoffman Award as the National League's top reliever last season, a testament to his dominance, our collective improvement in evaluating relievers, and the brilliance with which Milwaukee deployed its best pitcher. That latter factor was clear during the Brewers' terrific seven-game loss to the Dodgers in the NLCS, when Hader's availability and looming presence seemed to shadow the decision-making of L.A. manager Dave Roberts like a nagging cough. Hader struck out 143 batters last season in 81⅓ innings. He gave up 36 hits.
Andrew Miller, St. Louis Cardinals (L)
Position rank: 3
hWAR: 2.26
Hader usurped Miller's status as baseball's greatest lefty nuclear option. Miller just couldn't get healthy for any stretch of time during his last season for the Indians, spending time on the DL for a strained hamstring, right knee inflammation and a shoulder impingement. The lack of continuity showed in his numbers. Over just 34 innings, his WHIP rose from 0.38 to 1.38 and his ERA ballooned from 1.44 to 4.24. If Miller is healthy this season, St. Louis will have the kind of weapon to negate what division rival Milwaukee has in Hader.
Kenley Jansen, Los Angeles Dodgers (R)
Position rank: 4
hWAR: 2.19
The Dodgers gave Jansen spring training off last season, a statement that isn't as much of an exaggeration as it might seem. He started poorly, struggled with muscle pulls and a recurrence of old heart rhythm problems, and posted the worst season of his career. His 3.01 ERA tells only part of the story. Jansen gave up 13 homers in 71⅔ innings, more than twice the number of long balls he'd ever given up in a season. Too often, Jansen simply didn't know if his cutter would behave as it always had. His xwOBA on the pitch -- long one of the most devastating in baseball -- jumped from .223 to .271. The same number on his slider went from .089 to .240. Early reports from spring training have been encouraging, as spring reports so often are. Jansen has lost 25 pounds and has learned to use tracking data to amp up the spin rate on his pitches.
Blake Treinen, Oakland Athletics (R)
Position rank: 5
hWAR: 2.18
One thing that should have jumped out from the WPA chart used for the illustration above: Treinen was one of baseball's most improved performers in 2018. You can really trace his improvement to 2017, after he was traded to Oakland from Washington in the deal that sent Sean Doolittle and Ryan Madson to the Nationals. According to StatCast, Treinen has relied more on his four-seamer since moving to the A's and last season started throwing a cutter on about one out of every 10 pitches. His xwOBA on those offerings was .144. That's how you lead the majors in WPA.
Aroldis Chapman, New York Yankees (L)
Position rank: 6
hWAR: 2.12
Chapman's max-effort, blinding-speed game will never hold up over any length of time. Sure, it's impressive to see a guy who can come in and light up the radar, but there is more to succeeding on the mound than sheer velocity, especially as a pitcher ages and his stuff begins to diminish. ... OK, you've probably picked up on what I was doing there. Chapman, for lack of a more elegant term, is a freak. He's nine years into a successful career that has consisted of rearing back and blowing hitters away. But last season, some cracks appeared in his facade. Chapman's average four-seam velocity dipped below triple digits for the first time since 2013 and his xwOBA on those pitches rose from .275 to .352. He began to throw his slider more, and to good effect. This season, we might find out if that adjustment will hold up for a few more years of dominance or if hitters will finally start to get their revenge for all those years of whiffs.
Other Tier IV relievers: 7. Corey Knebel, Brewers (2.08 hWAR); 8. Craig Kimbrel, free agent (2.07 hWAR); 9. Felipe Vazquez, Pittsburgh Pirates (1.95 hWAR); 10. David Robertson, Philadelphia Phillies (1.83 hWAR); 11. Brad Hand, Cleveland Indians (1.78 hWAR); 12. Roberto Osuna, Houston Astros(1.70 hWAR); 13. Dellin Betances, Yankees (1.69 hWAR); 14. Zack Britton, Yankees (1.67 hWAR); 15. Sean Doolittle, Washington Nationals (1.64 hWAR); 16. Ken Giles, Toronto Blue Jays (1.61 hWAR); 17. Raisel Iglesias, Cincinnati Reds (1.54 hWAR); 18. Kirby Yates, San Diego Padres (1.53 hWAR)
Kimbrel is a future Hall of Famer and has been so good for so long now that you wonder if whatever he was asking for this winter was just out of whack for what any short reliever can get. That's especially true for a player who is coming off a career-worst 3.13 ERA, lost 2.5 strikeouts per nine innings off his 2017 figure and gave up a career-high seven homers. Then, when the Red Sox were in position to slam the door in the World Series, it was Chris Sale, not Kimbrel, who got the call. None of this is to say that Kimbrel can't be a top-flight reliever for a few more years. It's just to say that the rare certainty he always provided -- his most valuable trait, really -- might no longer be there. Whatever is going on, Kimbrel needs only to look at Greg Holland's 2018 travails as an example of why it's probably better that he get into a camp sooner than later.
As for Doolittle ... that's a heck of a good literary name, don't you think?
op from Tier V (role players):19. Matt Barnes, Boston Red Sox; 20. Brad Peacock, Astros; 21. Alex Colome, Chicago White Sox; 22. Ryne Stanek, Tampa Bay Rays; 23. Jeremy Jeffress, Brewers; 24. Jeurys Familia, New York Mets; 25. Will Smith, Giants; 26. Ryan Pressly, Astros; 27. Cody Allen, Los Angeles Angels; 28. Craig Stammen, Padres; 29. Wade Davis, Rockies; 30. Keone Kela, Pittsburgh Pirates; 31. Chad Green, Yankees; 32. Jose Alvarado, Rays; 33. Taylor Rogers, Minnesota Twins; 34. David Paulino, Blue Jays; 35. Archie Bradley, Arizona Diamondbacks; 36. Jose Leclerc, Texas Rangers; 37. Will Harris, Astros; 38. Seranthony Dominguez, Phillies; 39. Joe Kelly, Dodgers; 40. Matt Strahm, Padres; 41. Chris Devenski, Astros; 42. Scott Alexander, Dodgers; 43. Hector Rondon, Astros; 44. Mychal Givens, Baltimore Orioles; 45. Hector Neris, Phillies; 46. Shane Greene, Detroit Tigers; 47. Seth Lugo, Mets; 48. Tony Watson, San Francisco Giants; 49. Joakim Soria, Athletics; 50. Andrew Kittredge, Rays.
