clock menu more-arrow no yes

Filed under:

The Astros Have the Best Bullpen in Baseball.

New, 75 comments

And That’s a Fact Jack

MLB: Tampa Bay Rays at Houston Astros Troy Taormina-USA TODAY Sports

Who makes the best hamburger in the world?

McDonald’s of course. They sell the most, they have the most stores, in the most countries, with the most recognizable brand in the world. Their reputation is world wide.

But who among you, at least those of you from the Lone Star State, would take a Big Mac if right across the street you could have a fresh and hot double Whataburger with cheese, or maybe a fresh grilled Monterey Melt burger.

If you said McDonald’s go back to the hell hole from which you came and go get a tofu salad.

The Astros bullpen, like Whataburger, is not only great, it is one of the best kept secrets in Texas.

Seriously, in all the hoopla about the great Astros starting rotation, it seems the premier performance of the Astros bullpen has been greatly underappreciated. That’s a natural phenomenon in every fan base to some extent. Most fans just expect their bullpen to preserve every lead, but they get irate and indignant whenever the opposition bats do their job and score some runs to come from behind. That’s just not supposed to happen. Any pitcher that let’s that happen is a bum, thoroughly exposed like a corner back in football who gets burned on a post pattern.

It’s not supposed to happen, except it always does, even to the very best. Fangraphs says that this year’s AL premier closer, Seattle’s Edwin Diaz, has had five meltdowns, three blown saves, and even two losses. Why, if it weren’t for Diaz, the Mariners would be in first, not second place right now, said no one with a brain.

Still, I think that if most people were asked which team has the best bullpen in MLB, very few, even Astros fans, would pick our home town boys. After all, we’ve seen our guys’ meltdowns, we haven’t seen Diaz’ or Aroldis Chapman’s.

But I’m here to say that the Astros have the best bullpen in baseball. By that I mean the Astros bullpen as a group has done a better job of pitching than any other bullpen in baseball based on actual performance. No, they don’t have the best pedigree, they aren’t the most famous or glamorous pitchers, they don’t make the most money, and like Whataburger they don’t have the most name recognition outside of our great state. But so far, in 2018, the Astros have had the meatiest, tastiest, juiciest bullpen on the market. Nothing fancy, just basic quality. And for a pitching staff what that means is simple: stop the other team from scoring runs.

Every metric proves it.

Let’s start with the most obvious, the Earned Run Average. Of course, sabremetric purists have come to disdain this statistic and with some good reasons, but it still measures success of the most basic goal of a pitcher or pitching staff: how well did I (we) stop the other team from scoring runs. Of course pitching is not the only variable, but all would agree it is the main variable.

So how does the Astros bullpen compare? It is first in the American league. The Diamondbacks of Arizona do have the Astros beat by a microscopic fraction, but they are National League, home of the no DH, and in no other metric are they even in contention. The next best bullpen in the American League? The Yankees. Diamondbacks: 2.53 ERA. Astros: 2.58. Yankees: 2.77.

Here are two other metrics frequently cited to show the effectiveness of a pitcher or staff: FIP and xFIP. The first is fielding independent pitching, and the second is fielding independent pitching normalizing for home run luck. Both are designed to take the fielding component out of the evaluation of the pitchers. Again, by both measures the Astros are first, the Yankees second, the Diamondbacks way down the list. Astros FIP: 2.58, xFIP 2.96. Yankees FIP: 2.77, xFIP 3.10.

FIP and xFIP do not count batted balls except home runs in their equations. Other metrics, while also trying to take the variables of luck and fielding out of pitcher evaluation, take a more sophisticated approach, counting the quality of the batted balls, as well as the walks, strikeouts and home runs like FIP, xFIP. I will use two, SIERA, referenced by Fangraphs, and DRA, referenced by Baseball Prospectus.

Again, we are talking about the Astros and Yankees 1st and 2nd respectively in both categories . Astros SIERA: 2.64, DRA 2.38. Yankees SIERA: 2.78, DRA 2.77.

The following is a chart comparing the Astros relief pitchers in key performance areas to their near competitors. Included is WHIP (Astros first) and batting average against (second). I included mostly high ranking American League teams of interest to the Astros with a few National just for comparison.

Comparative Table, Team Bullpen Stats

Team k%/rank BB%/rank WHIP/rank LOB%/rank avg/rank ERA/rank FIP/rank xFIP/rank SIERA/rank DRA/rank
Team k%/rank BB%/rank WHIP/rank LOB%/rank avg/rank ERA/rank FIP/rank xFIP/rank SIERA/rank DRA/rank
Astros 30.5/2nd 6.4/1st 1.03/1st 80.9/2nd .212/2nd 2.58/2nd 2.65/1st 2.96/1st 2.64/1st 2.38//1st
Yankees 32.8/1st 9.4/17th 1.10/2nd 77.1/8th .195/1st 2.77/3rd 2.91/2nd 3.10/2nd 2.78/2nd 2.77/2nd
Brewers 28.2/3rd 10.2/24th 1.23/9th 78.7/4th .218/5th 3.12/4th 3.47/6th 3.38/3rd 3.29/4th 3.53/5th
RedSox 25.4/5th 9.4/16th 1.21/7th 78.4/5th .220/6th 3.17/5th 3.34/4th 3.72/5th 3.50/6th 3.94/8th
Cubs 23.7/10th 11.8/30th 1.30/13th 77.5/6th .218/4th 3.26/6th 3.81/12th 4.10/16th 3.99/22nd 4.69/19th
Athletics 22.8/17th 9.2/13th 1.31/14th 77.5/7th .240/14th 3.71/10th 4.19/21st 4.11/17th 3.81/18th 3.89/7th
Rangers 21.8/24th 7.9/6th 1.27/10th 71.4/23rd .242/15th 3.72/11th 3.61/8th 3.93/10th 3.70/12th 4.92/23rd
Mariners 26.2/4th 7.7/5th 1.22/8th 73.9/14th .235/11th 3.83/13th 3.60/7th 3.84/7th 3.28/3rd 3.29/3rd
Dbacks 21.5/25th 8.6/11th 1.15/3rd 82.8/1st .217/3rd .253/1st 3.65/9th 3.90/8th 3.72/13th 4.20/13th

Here are the main takeaways. The Astros are first in most categories, and second in all the rest. One remarkable pattern is the high strikeout rate, second, at the same time maintaining the lowest walk rate. That is almost like the pitching equivalent of last years’ Astros hitters having the 2nd most home runs and the fewest strike outs.

Also the Astros are among the best, second place, at keeping runners on base and not scoring based on their left on base percentage. Lest you think they have been lucky, they are third on this list in BABIP, only the Mariners and Rangers have a higher percentage of batting average of balls in play. The Astros’ BABIP is .292, the Yankees, .277.

What is also clear is that the Yankees, the McDonald’s of baseball, the standard, the Leviathon, are the main competition. Let’s break it down, mano a mano, pitcher to pitcher.

First, let’s keep in mind my opening analogy. These are the pitchers from the City That Never Sleeps. They have the pedigree, the reputation, the street cred, the shining lights in their faces, the stars by their names, the Best that Money Can Buy.

What I’m going to do is run the Yankees top six up against the Astros top six in the various overall categories, the pitchers most likely to be called upon in a playoff situation. Not their past performances, or their reputations, or what a computer thinks they will do in the future based on past performances, but what they have done so far this year. Its definitely a good fight.

The following chart compares the top six Astros and Yankees relievers by ERA. There was a minimum 27 innings.

Comparative Table, Astros Yankees Relief ERA

Astros player ERA/MLB rank Yankees player ERA/MLB rank
Astros player ERA/MLB rank Yankees player ERA/MLB rank
Collin McHugh 0.97/4th Aroldis Chapman 1.51/14th
Chris Devenski 1.32/11th Jonathon Holder 2.01/29th
Hector Rondon 1.50/13th Chad Green 2.11/35th
Brad Peacock 2.25/41st Delin Betances 2.78/78th
Ken Giles 4.08/194th Dave Robertson 3.38/125th
Will Harris 4.15/199th Chase Shreven 4.97/277th

As you can see, the Astros relievers 1-4 had lower ERA’s than their Yankee counterparts at the same positions. The Yankees were better only at position number 5. The Astros have 3 of the top 13 pitchers in all MLB in ERA on this list. Say what you will about the validity of the ERA statistic concerning relief pitchers, but we are comparing apples to apples here, Astros relievers to Yankees relievers. But as we shall see Ken Giles and Will Harris are vastly under performing their peripherals, but so are some of these Yankees pitchers. Let’s dig deeper.

The following is a ranking of these same twelve pitchers using the Baseball Prospectus DRA metric.

Comparative Table, Astros Yankees Relievers, DRA

Astros Player DRA/MLB rank Yankees player DRA/MLB rank
Astros Player DRA/MLB rank Yankees player DRA/MLB rank
Will Harris 1.64/3rd Aroldis Chapman 1.85/8th
Hector Rondon 1.69/5th Dellin Betances 1.89/10th
Brad Peacock 1.74/ 6th Chad Green 2.54/41st
Collin McHugh 2.09/ 16th Jonathon Holder 2.70/49th
Chris Devenski 2.12/ 18th David Robertson 2.93/65th
Ken Giles 2.80/57th Chasen Shreve 4.15/167th

This Baseball Prospectus statistic favors the Astros even more than simple ERA does. The Astros have three players rated before the Yankees have even one. Let’s hope that Will Harris actually performs as well in the future as this metric says he will. He has at times in the past. The Astros are better than the Yankees 1-6 in this comparison. They have 4 out of the the top 18 pitchers from this list in MLB by this metric.

Just to provide diversity to the statistical analysis and convince you I am not cherry picking from the most favorable metrics I will show you a comparison between the Astros and Yankees using Fangraph’s SIERA metric. Fangraphs claims it is more accurate than FIP or xFIP in their glossary defining SIERA. For this chart the rankings are based on 20 innings pitched.

Comparative Table, Astros Yankees Players SIERA

Astros Player SIERA/MLB rank Yankees Player SIERA/MLB rank
Astros Player SIERA/MLB rank Yankees Player SIERA/MLB rank
Brad Peacock 2.06/8th Dellin Betances 2.00/6th
Collin McHugh 2.12/10th Aroldis Chapman 2.05/7th
Will Harris 2.41/17th Chad Green 2.22/14th
Chris Devenski 2.59/24th David Robertson 2.90/38th
Hector Rondon 2.67/28th Jonathon Holder 3.12/56th
Ken Giles 3.01/44th Chasen Shreve 3.62/112th

SIERA is a little tougher in general, but a little kinder to the Yankees relative to the Astros. Their top 3 beat our top three, but in each, especially one and two, by a statistically insignificant margin. From 4-6 the Astros have the Yankees beaten easily.

Again, Astros relievers are dominating, with 5 of the top 28 pitchers in baseball from this list by SIERA. There are 30 teams in baseball. Each team should have one in the top 30, not five. Ken Giles is not far behind at 44th.

I could go on and on. If you go by xFIP the Astros have one in the top 10, four in the top 20, five in the top 33, and Ken Giles again comes in last among our top 6 at 42nd best in MLB. Again, if these positions were apportioned equally every team would have only one in the top 30 and 12 more would have two in the top 42. The Astros have 6. By xFIP the Yankees have 4 in the top 35, but Chapman and Betances are in the top 10.

I have one more chart. This one comes from Baseball Savant and uses Statcast data, specifically expected WOBA against (xWOBA). This is the weighted on base average that Statcast predicts each pitcher will surrender based on his batted ball profile so far this year. Like DRA, SIERA, xFIP etc. this metric tries to extract luck and fielding from pitcher evaluation. I would have used this in the team stats chart at the top except that Baseball Savant does not allow the user to divide starter stats from reliever stats. But we will compare the Yankee top six to the Astros’.

Comparative Table, Astros Yankees xWOBA

Astros player xWOBA/rank Yankees player xWOBA/rank
Astros player xWOBA/rank Yankees player xWOBA/rank
Devenski .230/4th Chapman .240/9th
Peacock .270/37th Betances .258/25th
Rondon .279/49th Holder .292/86th
McHugh .281/ 52nd Robertson .297/105th
Harris .298/108th Green .341/ 249th
Ken Giles .320/ 188th Shreve .349/275th

The Astros outperform the Yankees in every place in the ranking except second place. Ken Giles is actually considered the worst pitcher on the Astros by xWOBA, and yet he is considered well above league average.

In summary, the Astros bullpen as a whole has outperformed the rest of the league, and in particular the Yankees, in almost every relevant performance category and advanced metric. When you extract the top six bullpen performers from each team, the ones most likely called upon in playoff situations, and average their performances according to four metrics, ERA, DRA, SIERA and xWOBA, the Astros have lower numbers in every category.

ERA: 2.37 to 2.79. DRA: 2.01 to 2.67. SIERA: 2.47 to 2.65. xWOBA: .279 to .296.

One side note, but very relevant. There is much clamor for a name brand reliever like Brad Hand. Compared to our six Astros relievers Hand’s ERA (3.12) would be fourth best, his xFIP (3.41) would be seventh, Siera (2.53) fourth, and xWOBA sixth. I am not saying the Astros couldn’t use another pitcher like that, and we can expect that all the other contenders will try to upgrade their staffs as well. I am just trying to provide a little perspective on what the Astros already have.

Well, I think I’ve settled it. The Astros have had the best bullpen in baseball so far in 2018. If you can’t see it by now it’s because your eyes are blinded by the bright lights of Gotham City, or you’re staring up at the skyscrapers.

Is it really that simple?

OK, I hate getting beaten up by the commenters so I’ll make the logical case for the Yankees. Maybe their acclaim is not just because they are more famous and glamorous. The Yankees bullpen is rated slightly higher in fWAR than the Astros, 5.6 to 4.7. The value of the Yankees bullpen in dollars is $45.1 million, Astros $37.4. The Astros bullpen has lost more games, 12 -11, and blown more saves, 10-8. The Yankees are rated about average in the clutch rating, but the Astros bullpen is dead last.

But the best argument against the Astros lies in the fallacy of comparing the two groups as a whole, or even comparing the best six. Because the best two in the group should get more weight than the others. They are the ones that get the most use and have the most impact when everything is on the line.

The metrics I used above had quite a bit of variability. But one constant was the consistent top ten ratings of Betances and Chapman. Most of the Astros top six pitchers were top ten in some of the categories, none of them were top ten in nearly all of the categories like Betances and Chapman. The Yankees know that if they can get their starter a lead through seven innings, they can give the ball to Betances and Chapman and its probably game over. The Astros don’t have that kind of late game security.

OK, my rebuttal.

The higher WAR rating for the Yankees bullpen is due to its greater use. When normalizing for runs allowed per 9 innings the Astros bullpen actually has a slightly higher rating, 5.4-5.2.

Everyone knows by now how meaningless such statistics like wins and losses and saves or blown saves are by now, as they are dependent on so many other factors besides the quality of the pitching. If there were a huge difference in the loss number and blown saves number it would probably mean something. But the records are not that different even if slightly in the Yankees favor.

To the Astros credit they have the fewest meltdowns in MLB with 31, one less than the number two Yankees at 32.

Clutch ratings have long ago been proven to have no predictive value and are basically a reflection of luck. So maybe the Astros can hope to have better luck in the second half of the season.

The last argument, that Betances and Chapman are better than any one two combination the Astros have, has some merit, but let’s not forget these guys are human too. They have each had periods of inconsistency in their careers. We’ve seen Chapman meltdown in the World Series and the Astros themselves got to Betances for multiple runs just last year. Will Harris and Chris Devenski have been All Stars before, and Collin McHugh and Hector Rondon are currently putting up better ERA numbers than Chapman and Betances respectively.

And that gets me back to my original analogy. Chapman and Betances are the famous guys, the high dollar guys, the ones with the pedigree and reputation, playing for the most famous baseball franchise in the world with that special mystique. How could the lowly Collin McHugh and Hector Rondon ever hope to remain as good as these great Yankees, even if they have been as good for the first half of the season?

Projection services favor Astro regression and Yankee bullpen supremacy. Are they overlooking the best burgers in town for the familiarity of the pinstriped Golden Arches of baseball? Time will tell.