A Baseball Weblog

Monday, November 30, 2009

Classifying relievers, part 1

I am fascinated by relievers. I can’t exactly say why, but there’s something that I find, well, marvelous about the bullpen. I thought of trying to reason or explain my love of the bullpen, but I don’t think I can effectively do that. So let’s just leave it at that.
In this generation of the game, relievers are crucial in deciding games that are close and in the later innings. Into the late 1980s and early 1990s, as pitch counts became commonly tracked and complete games declined, relievers began to take on a much more important role. In the American League in 2009, approximately 3% of all games were
complete games, down from 16% in 1988.
With an increased focus on relievers, means of evaluation are important. There’s certainly plenty of debate as to what the best way of evaluating reliever performance is, but I actually wouldn’t like to look at that right now. Personally, I’d like to take a look at a reliever’s “role”: what the situation was when he entered, when he left, for how long did he pitch, etc. In this post, I’ll use some metrics that I think are useful for classifying members of the bullpen.


The simplest statistic I use when evaluating relievers is Average Innings Pitched per Game Relieved (AIPGR). It can be found by dividing the total innings pitched by the number of games relievers (IP/GR). It's not going to say a whole lot about the pitcher, but it will say something about how long a reliever pitched on average in a particular season. These days, it’s uncommon to see a reliever average over 2 innings per appearance, and the average over the past few seasons has been between 1 and 1.1 (it was 1.05 in 2009). Something that struck me was just how “specialized” relievers are now compared to in previous decades. Here is a chart that shows the AIPGR of the average big league reliever over the past 35 seasons.

That’s a pretty steep incline, especially around 1990. It’s not that surprising, considering pitch counts were first counted by STATS LLC in 1988. Similarly, the closer role has become more defined with the increase in specialized relievers. This graph shows the percentage of 2 inning+ saves since 1974.

Again, not that surprising, considering overall drop in AIP. But it’s still cool to see on a graph. At least I think it is.

Leverage Index

But really, how much else can you get from AIPGR? It would make sense that “specialty” relievers (“one-out-guys”) would have AIPs well under 1, closers would have AIPs around 1, and long-relievers would have AIPs well over 1. But AIPGR doesn’t say anything about the situation that the pitcher faced. That’s where Leverage Index comes in. LI is a statistic that shows the “pressure” of a particular situation, with 1 being the “average” situation. It would take me all day to figure out how to accurately and coherently explain it, so I’ll just refer you to this article by the metric’s creator, Tom Tango. Anyway, LI can be viewed in a number of different ways. Game LI (gmLI) shows the average leverage that a pitcher faced when entering the game; Play LI (pLI) shows the overall leverage that a pitcher faced; Inning LI (inLI) shows the leverage when the pitcher entered an inning; Exit LI (exLI) shows the leverage when the pitcher left the game. For the purpose of showing a pitcher’s role, I think it is most effective to use gmLI, as that shows the situation that the pitcher’s manager wanted him to face. Before I go on, here is a chart to show the difference in pLI/gmLI since 1974.

There’s not a whole lot of difference between pLI, but the gmLI numbers have dropped precipitously. This would lead me to believe that in previous decades, relievers were used primarily to get out of jams created by starters, while they are more commonly used to start clean innings these days.

Using both of these things

This graph shows all qualified* relievers since 2005 in terms of AIPGR and gmLI.
*either 50+ IP, 50+ GP, or 20+ saves (there are only two of these pitchers that don’t fit the other requirements. I included them because I will be looking at closers in a future post.)

This pretty much confirms what I said earlier. The highest concentration of pitchers with gmLI over 1 are those that have AIPs around 1; I’d guess those primarily closers. To left are the lower AIP pitchers, the specialist, and they seem to have slightly lower LI marks than the closers. And way over to the right have AIPs well under 1, for the most part.

So, we’ve looked at the average length of reliever appearances through AIP and the average “pressure” faced by the pitcher through LI. In my next post, I’ll scratch the surface a little bit more than I did here, as this was just an introduction. I’ll look at some MLB averages and specific examples.

Data is from Fangraphs and Baseball-Reference.

Friday, November 20, 2009

A look at Phil Hughes through PITCHf/x

Ask anybody who followed the Yankees in 2009, and they’d tell you that one of the most important decisions the Yankees made in 2009 was moving Phil Hughes to the bullpen. Hughes had begun the year as a starting pitcher at Triple A Scranton before getting called up by the Yankees in late April. He pitched well enough in his 8 starts, save for one terrible outing against Baltimore in May that put his ERA at 5.45 through the end of May. When the historically bad Chien-Ming Wang made his much anticipated return to the rotation on June 4th, the Yankees were left with this important decision of sending him back to Scranton, where he would’ve been a starter, or moving him to the bullpen, where he would attempt to shore up a relief corps that was not one of the Yankees’ strengths over the first two months. The Yankees decided to keep him on the active roster and make him a reliever, and it would be an understatement to say that that move paid off. All Hughes did was rack up 65 strikeouts and a 5.00 K/BB ratio over 51 1/3 relief innings to go along with a 1.40 ERA, 1.83 FIP, 0.86 WHIP, and .176 opposing batting average. He worked primarily out of a middle relief role in June before dethroning Brian Bruney in July as the Yankees’ primary setup man. For the final three months of the regular season, Hughes was about as good as it gets. He was the Yankees' most valuable reliever behind Mariano Rivera in 2009 and ranked 1st among major league relievers in ERA, FIP, and WHIP. Out of the bullpen, his velocity spiked and he missed more bats, which led to greater success. Let’s take a closer look at his 2009 numbers through PITCHf/x.

Phil Hughes - Starter
Pitch Data

PitchAverage Speed (mph)Max Speedpfx_xpfx_zspin_dir

Hughes primarily used a four-seam fastball, a cutter, and a curveball, mixing in a few two-seamers and changeups along the way (the two-seam clusters probably aren't perfect, since his two kinds of fastballs seemed to "blend together" in terms of spin movement). Here are how his pitches fared in the rotation.

Pitch Results

PitchPitch#Pitch%Swing%Whiff%Wide Zone%Chase%Watch%SLGCONRSvRSv/100


The high SLGCON and run value numbers show that Hughes wasn’t that dominant in his starts. Sifting through the numbers, something that struck me was the 17% whiff rate on fastballs, which is noticeably above the league average of 14%. A look at the strikeout breakdown below shows that he was about as comfortable picking up strikeouts on the fastball as he was on the curveball.

Strikeout Breakdown



Here are your graphs and tables from Hughes’ bullpen stint, which began on June 8th.

Phil Hughes - Reliever
Pitch Data

PitchAverage Speed (mph)Max Speedpfx_xpfx_zspin_angle

Pitch Results

PitchPitch#Pitch%Swing%Whiff%Wide Zone%Chase%Watch%SLGCONRSvRSv/100


Just about everything here is greatly improved. The velocity on the four-seamer and cutter was up about 2 mph on average, and the cutter had more horizontal and vertical break. The whiff rates for both pitches also rose drastically. Notice also that Hughes ditched the two-seamer and changeup out of the bullpen (the two two-seamers and one changeup picked up by PITCHf/x are from his long relief appearance against Boston in early June). What’s strange is that Hughes didn’t like the curveball that much out of the bullpen. Here’s the strikeout breakdown:

Strikeout Breakdown



That’s a lot of fastballs for strike three. His “K pitch” out of the bullpen was far and away the swinging strike on the four-seamer. In addition, Hughes began to throw more fastballs as the season wore on, as evidenced by this cumulative pitch selection chart.

So, what does all of this say about Hughes’ strange 2009 season? A switch to the bullpen turned him from a decent, low 90s fastball/curveball guy into a strikeout pitcher who loves his 95 mph heater. And what does it say about his future? The Yankees see him as a starter in the long run, so it would not surprise me to see some of these numbers (particularly the fastball velocity) decline. Ideally for Hughes, the successful bullpen experiment will have given him enough confidence in his arsenal to be able to consistently attack hitters as a starter.

Gameday PITCHf/x data is from MLB Advanced Media; it can be easily accessed via this tool. Other statistics are from Fangraphs and Baseball-Reference.

More reading: River Ave. Blues did a great piece last month on Hughes and his pitch selection.

Sunday, November 15, 2009

The awards, according to me

Beginning tomorrow, the recipients of our favorite baseball awards will be announced. I have prepared my own ballot. (Yes, I know, I technically would have to have done this about six weeks ago, but I’m not part of the BBWAA, so I’ll just do it this way. Ha.) Anyway, here it is.

1. Andrew Bailey
2. Elvis Andrus
3. Brett Anderson

1. Tommy Hanson
2. Chris Coghlan
3. Andrew McCutchen

1. Mike Scioscia
2. Don Wakamatsu
3. Ron Gardenhire

1. Jim Tracy
2. Bruce Bochy
3. Joe Torre

1. Zack Greinke
2. Felix Hernandez
3. Justin Verlander

1. Tim Lincecum
2. Chris Carpenter
3. Adam Wainwright

1. Joe Mauer
2. Derek Jeter
3. Mark Teixeira
4. Ben Zobrist
5. Jason Bay
6. Zack Greinke
7. Alex Rodriguez
8. Ichiro Suzuki
9. Miguel Cabrera
10. Kendry Morales

1. Albert Pujols
2. Prince Fielder
3. Hanley Ramirez
4. Pablo Sandoval
5. Ryan Braun
6. Ryan Howard
7. Andre Ethier
8. Chris Carpenter
9. Matt Kemp
10. Todd Helton

Saturday, November 7, 2009

The Yankees' offseason

Congratulations to the World Champion New York Yankees. In my mind, they are the deserving champions, as they were clearly the best team in the major leagues for much of the 2009 season. As a Yankee fan, I must admit to a bias, since they were the team that I followed throughout the year. That being said, it was remarkable that to me that they never seemed like they were ever out of a game, especially at home. That's been the case for many years, though --- the big difference this year was the acquisition of two strikeout-type pitchers (both had varying levels of brilliance during the postseason) and sure-handed first baseman that was also an offensive sparkplug. Obviously, they had contributions across the board in 2009, but where do you think the team would be if they didn't have CC Sabathia, A.J. Burnett, and Mark Teixeira?
But, I actually would not like to reflect on 2009 (right now) - I'd like to look ahead to 2010 (already). The team has plenty of offseason challenges ahead; two notable decisions the Yankees have to make involve Johnny Damon and Hideki Matsui. As great a hitter as Matsui is, I don't see him coming back with the team next year. The Yankees seem intent on getting "younger and more athletic," and one way to do that is to clear up the DH slot. I think it's more realistic to see Damon back in pinstripes next year, even if it is only for one year. If the Yankees were to resign Damon and let Matsui walk, Damon could more easily slide into the DH role when needed (do you really think he can play the outfield every day all season long?) and possibly give more playing time to better defenders. And who are those better defenders? It's possible that the Yankees take a look at Matt Holiday, who played above-average defense last year. I don't get the feeling that the Yankees are that high on Brett Gardner as a hitter, even though he did hit .270 with an OBP of .345. I figure Austin Jackson will see some playing time next year, even if he doesn't start the year with the club.
The outfield is only one thing the Yankees have to sort out for next year. Although the bullpen was arguably the best in baseball this year, two guys that really helped them along at some point or another in the year, Phil Hughes and Joba Chamberlain, look like they're headed to the rotation. This leaves the Yankees with David Robertson, Damaso Marte, Phil Coke, and Alfredo Aceves as in-house setup options. Personally, I wouldn't be surprised if we see Joe Girardi "mix'n'match" those guys at the beginning of the season, and then see which one excels the most. I think Marte will become the primarily lefty, with Coke going into the longer role that he had in 2008 and at the beginning of this season. I think it's quite possible that we see American League K/9 leader David Robertson slides into an 8th inning role. Of course, the Yankees could always go out and get a late-inning reliever to set up Mariano, but with the exception of Tom Gordon in 2004, that hasn't seemed to work out too well for the Yankees in recent years (Kyle Farnsworth, Luis Vizcaiano, LaTroy Hawkins come to mind ...).
Finally, starting pitching. We've got Sabathia and Burnett, and most likely Chamberlain and Hughes. I'm becoming increasingly convinced that Andy Pettitte will announce his retirement sooner rather than later, and if that does happen, there would be at least one vacancy in the starting rotation. The Yankees do have some young pitchers (Zach McAllister, Ivan Nova, Ian Kennedy) that could possibly fill a #5 slot in the rotation, though probably not in April. John Lackey might be getting some calls from the Yankees' brass; that would certainly be a nice addition for the club, but I wouldn't count on it.
Granted, these are not huge issues - most of this World Championship team will be returning. But, the Winter Meetings are only a month away, so we might as well begin thinking about the Hot Stove.

Monday, November 2, 2009

2009 Runs Saved Leaders

One of my new favorite baseball metrics is batting runs, which attempts to value the contribution of each play by calculating the average runs scored in an inning before and after that play occurred. It can also be applied to a particular count, which is what I’m going to look at here. (I have some links at the end of the article that provide a better explanation and discussion about this metric.) In the middle of last season, Fangraphs added a “pitch value” statistic that measures the value of each pitch thrown in terms of batting runs (or linear weights, which name you prefer). It’s an extremely useful tool, as it can tell what the most effective fastball, curveball, changeup, slider, splitter, or knuckleball was in terms of run expectancy. I figured that if you summed up the values for all the pitches, it would give you a pretty good idea of who was the most effective pitcher in the season. So here, thanks to Fangraphs, I have compiled the list of 2009 leaders and trailers in terms of Runs Saved and Runs Saved per 100 pitches (2000 pitch minimum for starters, 650 for relievers):

Tim Lincecum55.1
Chris Carpenter49.6
Zack Greinke45.8
Javier Vazquez43.6
Dan Haren38.2
CC Sabathia37.2
Clayton Kershaw36.7
Josh Johnson36.4
Felix Hernandez36.1
Ubaldo Jimenez34.9

Jeff Suppan-27.6
Manny Parra-27.6
Jason Berken-26.7
Fausto Carmona-25.6
Braden Looper-25.4
Jeremy Guthrie-18.5
Scott Richmond-17.9
Luke Hochevar-17.5
Gil Meche-17.4
Trevor Cahill-16.3

Chris Carpenter1.86
Tim Lincecum1.60
Zack Greinke1.32
Javier Vazquez1.32
Clayton Kershaw1.23
Josh Johnson1.11
Dan Haren1.10
CC Sabathia1.04
Felix Hernandez0.99
Ubaldo Jimenez0.98

Jason Berken-1.31
Fausto Carmona-1.13
Manny Parra-1.08
Jeff Suppan-1.01
Scott Richmond-0.79
Braden Looper-0.78
Gil Meche-0.76
Luke Hochevar-0.74
Armando Galarraga-0.68
David Huff-0.66

How about the relief pitchers in 2009:
Andrew Bailey26.3
Jonathan Broxton23.5
Phil Hughes19.9
Trevor Hoffman19
Nick Masset19
Joe Nathan18.9
Jeremy Affeldt18.9
Heath Bell18.7
Michael Wuertz18.4
David Aardsma17.9

Brad Lidge-16.7
Chris Ray-13.5
Brian Bass-12.9
Jeff Bennett-11.9
Scott Linebrink-11.1
Ron Mahay-11
Matt Capps-8.9
R.A. Dickey-8.7
Santiago Casilla-8.4
Ron Villone-8.1

Trevor Hoffman2.55
Phil Hughes2.38
Andrew Bailey2.09
Jeremy Affeldt1.96
Jonathan Broxton1.92
Huston Street1.87
Darren O'Day1.85
Nick Masset1.78
Mariano Rivera1.74
Claudio Vargas1.72

Chris Ray-1.72
Brad Lidge-1.46
Jeff Bennett-1.39
Ron Mahay-1.21
Scott Linebrink-1.05
Santiago Casilla-0.99
Matt Capps-0.95
Rafael Perez-0.90
Brian Bass-0.87
Ron Villone-0.87

As you can see, these jive pretty well with who would often be considered the “best pitchers” of the year.