Archive for July, 2005

Advanced Relief Pitching Primer

When asking what the most important statistic for a relief pitcher is, one could expect a variety of answers, from the commonplace (wins, saves, holds) to the relatively complex (DIPS, RSAA). In sabermetrics, you won’t get a lot of disagreement if you say that an ERA is a good starting point and that a high strikeout-to-walk ratio is always healthy. But most other people, save those who read The Hardball Times or Baseball Prospectus on a regular basis (which I imagine many of you do), don’t have a clue beyond that.

ERAs are great to use, and they tell us a lot, but I think Win Probability Added (WPA) can tell us even more. (I know this is a review for many people, but I feel compelled in this explanation to include those who may not be familiar.) WPA accounts for the criticality of an appearance, based on researched win expectancy tables for different scores and base-out situations. A run allowed to the home team in a tie game, bottom of the ninth, is (needless to say) more important than a run allowed when you’re up 12-2. Not all runs are created equal, so finding the win probability added in a situation tells us a bit more than ERA.

To understand WPA, it’s also helpful to understand its cousin, P. “P” refers to the amount of win probability that could potentially be added by a reliever if he comes into the current situation and finishes the inning without allowing a run. For reference, a bases-loaded situation in a tie game with no outs in the top of the 9th has a P of .473 (given an average NL run environment), while the same situation with two outs and no one on has a P of just .032. Also, a “save situation” 5-2 lead to start the top of the ninth is just .033.

To my knowledge, there have been few (if any) studies on pitchers’ WPA tendencies, so whether certain pitchers tend to be better performers in the clutch or not (at least better than their ERAs would suggest), I have no idea. Accounting for this crucial aspect of the game (the specific situation) does seem to make sense, though, and if nothing else, it gives Braves fans one more reason to despise Dan Kolb. At any rate, I started tracking WPA and P for the Braves out of a slight curiosity, and I’ve managed to turn it into quite an undertaking. It’s an enjoyable activity, but it’s very time-consuming, so the Braves are the only team I track.

Moving on, it’s important to understand that pitchers with high average “P” have more chances to help (or hurt) their WPA. Based on this important premise, I have started tracking several other stats to give WPA a bit more meaning. (Those of you who follow THT may have been familiar with what I’ve been talking about up to this point, but this should be new for just about everyone, unless you frequent my website.)

I account for the “P difference” by dividing WPA by P for two separate stats: WPIP and WPTP, which stand for Win Probability over Initial P and Total P, respectively. For WPIP, I simply divide by initial P, which was my starting point. For WPTP, I divide by total P, which is the P for each inning added up. The result is a rate stat that tells us how much of a pitcher’s P he is actually able to convert into WPA, which is especially useful for comparisons on the same team (where pitchers have varying average Ps). A side effect of the decision to track WPTP was a little added relevance for these stats for starting pitchers (because of the number of innings they pitch per appearance).

I track a few other made-up stats other than these, but they’re not as interesting for the purposes of this discussion. Instead, I’ll close with a few relief pitching leaderboards for comparison’s sake: saves, holds, WXRL (BPro’s version of WPA, expected wins added over replacement level), leverage (BPro’s version of P, which compares situations to the start of a game), and ERA and FIP for relievers with at least 30 innings and at least one save or hold.

Chad Cordero 4.462 Francisco Rodriguez 2.35 Mariano Rivera 0.85 Rudy Seanez 1.94 Chad Cordero 34 Scot Shields 22
Francisco Rodriguez 4.404 Bob Wickman 2.19 Chad Cordero 1.17 Mariano Rivera 1.97 Joe Nathan 28 Julian Tavarez 22
Scot Shields 3.775 Ugueth Urbina 2.19 Huston Street 1.41 Kyle Farnsworth 2.29 Jason Isringhausen 28 Ryan Madson 22
Derrick Turnbow 3.334 Joe Nathan 2.18 Mike Timlin 1.44 Francisco Rodriguez 2.35 Trevor Hoffman 27 Mike Timlin 18
Jason Isringhausen 3.301 Trevor Hoffman 2.14 Todd Jones 1.45 Brad Lidge 2.35 Mariano Rivera 25 Luis Ayala 18
Dustin Hermanson 3.298 Chad Cordero 2.07 Eddie Guardado 1.59 B.J. Ryan 2.48 Jose Mesa 25 Scott Eyre 18
Mariano Rivera 2.818 Dustin Hermanson 2.01 Dan Wheeler 1.6 Arthur Rhodes 2.56 Bob Wickman 25 Tom Gordon 18
Eddie Guardado 2.738 Scot Shields 2.01 Roberto Hernandez 1.61 Chris Reitsma 2.58 Francisco Rodriguez 24 Gary Majewski 17
Bob Wickman 2.632 Jose Mesa 1.99 Cliff Politte 1.71 Roberto Hernandez 2.61 Brad Lidge 24 Ron Villone 16
Brian Fuentes 2.593 Akinori Otsuka 1.97 Jason Isringhausen 1.73 Trevor Hoffman 2.61 Eddie Guardado 23 Juan Rincon 16

A few notable things from the data:

Several players have been getting “cheap” saves or holds: Jason Isringhausen (3rd in saves, 19th in leverage) and Julian Tavarez (T-1st in holds, 55th in leverage) for the Cardinals, and Ryan Madson (t-1st in holds, 52nd in leverage) of the Phillies. At the other end of the spectrum are players who are really earning their keep, such as K-Rod, who is just 8th in saves, but first in leverage (and consequently 2nd in WXRL).

There are a few unheralded names on the WXRL list, including Scot Shields, Derrick Turnbow, and Brian Fuentes, who really doesn’t get enough credit for the great job he does for the Rockies.

Next week, I will be fresh off my yearly trip to see the Braves in person (Saturday’s game against the Pirates). I’ll come back with a report for everyone, as well as some more relief pitching analysis.

The Hardball Times stats page
Baseball Prospectus stats page
You should also check out Dave Studeman’s articles on Win Probability and P at THT.

Pitcher Control Over BABIP, Ceteris Paribus

After writing my article Another Look at DIPS back in May, several readers contacted me to say that I needed to see a few studies at Baseball Prospectus on the subject. I agreed. I was willing to see any study on the subject. However, I’m not a BPro subscriber. It’s nothing personal, I’m just cheap. And though I could have acquired the studies via friends I decided that violated my ethical code regarding intellectual property rights. (And I’m not trying elevate myself to some moral high-ground here, I just have a nasty guilty conscience that I try to avoid.) So, I asked the authors of the studies to send me copies. One did not respond, the other responded as though I had not requested to see the study. This is perfectly acceptable, and I have no problem with it. Why give me something free that others have paid for? I’m all for capitalism and making money. As libertarian and an economist, I can’t complain too much. But, in the interest of seeking truth I want other people to know that I was not just ignoring these studies.

Thankfully Baseball Prospectus is currently running a nice promotion to generate subscriptions by letting potential subscribers see what they are missing. (Maybe they’re just being altruistic…nah!) It just so happens that this has a nice side benefit in allowing me to see these studies. So, just yesterday, I was able to read three studies by Clay Davenport (here) and Nate Silver (here and here).

Both of these studies suffer from the same problem: failure to employ the ceteris paribus assumption. The Latin phrase, which means all other factors remaining constant, is an important caveat in understanding DIPS. DIPS theory is about pitcher control over hits on balls in play as a skill separate from defense-independent statistics. It’s very easy to interpret DIPS as saying just that pitchers have little control over balls in play. That’s almost correct, but not quite. DIPS theory tells us that after controlling for a pitcher’s defense-independent pitching statistics (the holy trinity being: strikeouts, walks, and home runs) knowing a pitchers BABIP tells us very little about a pitcher’s ability to prevent hits. In fact, I find in my study (so did Voros when we last heard from him on the matter) that pitchers do have control over balls in play. It is just that this control is captured in the DIPS metrics. In particular strikeouts are very important predictors of a pitcher’s ability to prevent hits on balls in play. As I wrote,

While pitchers may have some ability to prevent hits on balls in play, the effect is small. And any effect a pitcher does have is reflected within DIPS metrics.

Ceteris paribus, pitchers don’t seem to have any control over balls in play. DIPS is useful not just because it tells us what pitchers do on balls not put into play but because it says something additional about what happens when the ball is in play. So, how does this apply to these other studies.

Davenport looks at the difference in hits on balls in play in the minor leagues. He attempts to see if pitchers who will one day pitch in the majors have control over balls in play that non-major leaguers lack. If so, then maybe having control over hits on balls in play is a very important skill that major league pitchers have. It’s just that once they reach the majors this skill is not observable since it maxes out at the highest level of competition. It’s quite an excellent idea for a study. However, what Davenport concludes from the data he presents does not mean that major league pitchers have more control over balls in play than minor leaguers separate from their DIPS. It is true that at every level of the minors, the major league pitchers seem to have a superior batting average on balls in play by a small amount. However, it’s also true that this same group has more strikeouts, and strikeouts are associated with fewer hits on balls in play. We need multiple regression analysis to see if major league pitchers have more control over BABIP while holding DIPS constant. Otherwise, it is likely the case that the observed differences in BABIP are the product of DIPS not despite them. I don’t have the data, otherwise I’d look into it.

Silver also looks at differences in BABIP, but he focuses on difference types of major league pitchers. He looks at lists of pitcher with excellent change-ups, cureveballs, and fastballs. Surprisingly, all of these types of pitchers have a tendency to have lower BABIPs than expected. Well, again that’s really no surprise. I suspect all of the these guys had good DIPS numbers too.

The moral of the story here is ceteris paribus: holding other factors constant. When trying to determine if control over hits on balls in play is a distinct skill, we much control for the impact of the DIPS metrics that we know do influence this ability. This critique does not render these past studies wrong, but opens the door to further research. I encourage others to continue the work.

Guest Bloggers

I’m going to be taking a little vacation for a few days, so I’ve asked Kyle Sturgeon and John Wright to guest blog for the next two weeks. I’m happy they agreed. I may be lurking around some. But if the sun is out on the South Carolina coast, I may not feel like logging on. I’m not sure how much either will post (they have no obligation to post anything) but I’m sure whatever they have will be worthwhile.

Kyle, often known as “Kyle S” on many a baseball message board, is big Braves fan with a lot of baseball knowledge. He works in DC but is not part of “the problem.” And, like me, has a young daughter — my little girl can do the tomahawk chop already.

John Wright runs the most in-depth website on the Braves bullpen that there is. He’s a college student from nearby Chattanooga.

So, let’s give a warm welcome to Kyle and John. I’m happy to have them both on board. I know they’ve got some good stuff cooked up. Plus, they can’t be as bad at spelling as I am. One of the fun things about running a blog is meeting intelligent, nice people who share similar interests. These guys are perfect examples of the kind of people you meet.

Braves Notes

I’ve got a few things that are worth blogging about, but they’re short, general, and mostly about the Braves. So, I’ll throw them in here.

  • Baseball Digest Daily has an interesting interview with the Braves 2005 first round draft pick, Joey Devine. Devine is a relief pitching prospect out of NC State who seems to defy the mold of the traditional Braves draft pick. He’s a college closer who’s on the fast track to the majors. Some people think he will be there this year, but I doubt it. After breezing through Myrtle Beach, he’s also played well for Mississippi, only giving up one run in 10 2/3 innings. He’s yet to along a longball and his K/BB is 11/7. If he plays well I can see him getting an audition for the playoffs in September, but I don’t think he’ll be in the big leagues any time soon. But that’s what I though about Francoeur.
  • Speaking of Jeff Francoeur, the guy is doing all he can to punish me for saying he’s not ready by jacking 3 bombs in 26 at-bats. So what am I going to do? I’ll stick to my belief that he’s not ready. There’s no doubt that Jeff has power, but as soon as pitchers figure out that they don’t have to throw him strikes he is going to struggle. If they could hold him to .275/.322/.487 in AA, he’s not going to bust out in the majors. 26 at-bats is a tiny sample size, and I don’t think we should take them as evidence that he’s ready over his AA performance.
  • Which leads into the next thing on my mind, and that is the Braves have been rumored to be interested in Rondell White. I was kind of surprised to hear this, but I was even more surprised when I looked up his numbers this year. He’s playing regularly against right-handers and posting a .310/.344/.467 line. What’s even more interesting is that he’s playing better at hitter-unfriendly Comerica Park with a .313/.358/.527 line. PrOPS says his stats are not fluky either. White might be a nice pick-up for the stretch run, especially with Atlanta’s left-hand heavy team. I think the Braves would have to give up very little for him. White has also spent less of his time DHing this year, playing a good bit of outfield. If a deal does go down, I think it would send Francoeur to Richmond where he can get the at-bats he needs. This deal makes a lot of sense.
  • If you’re interested in the Nats recent press over RFK’s dimensions, check out Michael McCann’s take on the legal ramifications. Maybe Carlos Guzman and Vinny Castilla need to hire a lawyer to sue for their suckiness. It’s funny how bad RFK has played this year. The general assumption was that it would be a slight pitcher’s park. Baseball Prospectus guessed it’s park factor would be 980, but it’s been closer to 900.
  • Congrats to Greg Maddux on his 3,000th strikeout. That’s a lot for a guy who “doesn’t strikeout a lot of guys.” He’s 13th all-time is strikeouts in MLB history, and has been in the top-10 in Ks seven times. Once again, it’s a reminder that the first counter-example brought to the table to prove DIPS wrong is actually the poster-boy for why DIPS is right. Let’s not forget he’s a master at limiting walks and home runs, which makes his strikeout totals more amazing. He strikes guys out by putting the ball in the zone.

The Braves Need Pitching

“What?” you say. The Braves are third in the NL, sixth in the majors, with an ERA of 3.72. On top of this, the Braves have pitching coach Leo Mazzone to smooth over any problems. And let’s not forget that John Thomson will be coming back, and Hudson and Hampton are already back (although, Hampton may be back on the DL soon). The Braves have had decent pitching coupled with good luck to put them where they are. Just look at the Braves peripheral stats by starters and relievers.

The Starters
Starting pitching has been the strength of this team, but it reality it’s been decidedly average. Here are the individual stats for the Braves starters. This excludes Seth Greisinger (who’s now in the Far East), and the stats for Sosa and Colon are as starters.

Pitcher		HR/9	BB/9	K/9	K/BB	ERA	FIP
John Thomson	0.36	2.52	5.76	2.29	3.42	3.28
John Smoltz	0.62	2.28	6.77	2.97	2.64	3.34
Mike Hampton	0.74	2.36	3.54	1.50	2.51	4.27
Tim Hudson	0.74	3.87	5.16	1.33	3.59	4.41
Kyle Davies	0.62	4.94	5.86	1.19	4.32	4.43
Roman Colon	1.54	1.54	5.79	3.75	3.09	4.66
Jorge Sosa	1.26	3.98	6.70	1.68	2.51	4.85
H. Ramirez	1.45	2.90	2.83	0.98	4.57	5.64
Total		0.88	3.04	5.16	1.70	3.41	4.34
NL Average	1.00	3.20	6.40	2.00	4.33	4.33

While the Braves post some nice ERAs, their FIP ERAs are worse, with the exception of Thomson. Getting Thomson back will be huge, but the gain of Hampton and Hudson aren’t much of an improvement over the guys who have been filling in for them. Don’t get me wrong, I would rather have Hudson and Hampton over Sosa, Davies, or Colon in the rotation; but, I’m not sure how much things will improve. Horacio Ramirez has been awful and awfully lucky. I would feel comfortable with any of the replacement starters over him, especially if the Braves can find someone to trade him to for a decent bat. The Braves are very deep with starters, especially now that Colon has shown he can throw a lot of innings. While HoRam may be a serviceable 5th starter, I suspect some teams think he has more of an upside. Trade him while you can, JS. You’ve got plenty of replacements who certainly are no worse.

The Relievers
The relief corps has almost completely turned over since the start of the year. The bullpen has been a problem, but the Braves have simply changed the brand of bubble gum they’re using to patch holes in the hull. Here’s a look a the relievers who are currently on the team, and their 2005 relief stats.

Pitcher		HR/9	BB/9	K/9	BB/K	ERA	FIP
Macay McBride	0.00	0.00	6.75	1.00	0.00	1.38
Chris Reitsma	0.20	1.76	5.83	3.33	3.32	2.77
John Foster	0.94	4.24	8.84	2.11	3.30	3.99
Blaine Boyer	0.60	5.40	7.20	1.33	2.40	4.27
Jorge Sosa	0.38	7.13	6.00	0.84	2.63	4.78
Dan Kolb	0.71	5.65	5.82	1.04	5.42	4.80
Jim Brower	1.38	3.46	6.92	2.00	2.77	4.82
Jay Powell	0.00	17.14	3.86	0.25	0.00	7.96
Adam Bernero	0.96	2.30	7.09	3.08	6.51	3.77
Roman Colon	2.57	4.29	6.43	1.50	7.71	6.91

All		0.57	4.48	6.47	1.44	3.52	4.08
Roster		0.83	4.01	6.59	1.64	4.53	4.28
NL average	1.00	3.20	6.40	2.00	4.33	4.33

I include Bernero and Colon because there is a decent chance these guys will appear in Atlanta again this year, especially if an injury occurs. The Braves are not keen on bringing up starters to the pen. The All and Roster rows are the bullpen stats with and without these two. Again, the Braves are decidedly average in FIP, although I have to praise the Braves for keeping the ball in the park. Both the pen and the main starters are doing well in this area. It’s not a park factor phenomenon either. Turner Field has been a slight hitters park for home runs this year.

It would be nice to see the Braves add an arm to the pen for the stretch run. The NL East is still tight, and I’d like to see a strong team make it to the playoffs.

Addendum: In case any of you haven’t read the comments yet, you should. Kyle Sturgeon and John Wright have posted some interesting studies on general pitching (Kyle) and Braves relievers (John). Kyle has found an interesting way to predict future success for pitchers, and John has some interesting graphs on Braves relievers using WPA. Good work guys.

Efficient Efficiency

My latest article at The Hardball Times is up: Moneyball and Efficient Efficiency.

The A’s focus on college players not because of a bias of stat-heads in thinking college players are superior to high school players; but because they are more predictable based on the statistical tools the A’s favor. A technological innovation in performance scouting, such as DIPS, can increase the efficiency in evaluating talent. DIPS ERA can be used to better predict a college player, but maybe not a high-school player.

As a result, the A’s are going to have a higher confidence when drafting from this talent pool. And if a technology can be employed in one area but not another, it’s no surprise that the A’s would concentrate on a talent pool where this new technology is useful. Just as the cotton gin caused southern farmers to switch to cotton farming, where the technological innovation could be used, so too did the A’s turn to the college talent pool where it’s inventions were useful.

If you have any comments, please leave them in the comments section.

Growing Power

Dan Fox of Dan Agonistes posts one of the best sabermetric studies I’ve seen in some time over at The Hardball Times today. He uses to Sean Buroughs and Mark Teahen as foils to examine the popular belief that players acquire power.

To me this is hopeful since it shows that in the recent past there have been several infielders like Smalley, Whitaker and Harrah, as well as outfielders like Puckett and Clemente, who have developed more than average power after being in the league a few years and after the age of 24. And if you move the cutoff to 23 instead of 24, you’ll also find that George Brett fits the mold. So historically speaking, it’s not out of the question that Teahen and Burroughs will live up to the announcers’ expectations.

If you don’t read this study, may your favorite team play Brian Jordan in the outfield everyday for the next three seasons.

Baseball Analysts: Mid-Season 75

Bryan Smith reviews the his top-75 prospects at mid-season ( 1-30, 31-75). Here’s a sample on Jeff Francoeur.

19. Jeff Francoeur: Atlanta Braves (OF)- 21
AA (SOU): .275/.322/.487, 21/76, 13 SB in 335

Now in the Majors, Francoeur homered in his first game against the Cubs. He has a bunch of flaws as a player — both contact and selectivity — but makes up for it in raw talent. Still, you have to wonder how long we’ll be justifying walk rates with that comment. The Braves are huge believers in Francoeur, and have all-but-decided that he, Kelly Johnson and Andruw will make up the 2006 outfield. Expect Jeff to have the, by far, worst numbers of the group.

He also reports on Marte, McCann, and Saltalamacchia.

When You Stray from What You’re Good At…

Skip over at The Sports Economist points to Theo Epstein’s latest off-field endeavor with his brother, Paul. It’s “A Foundation to Be Named Later,” and it’s designed to help disadvantaged kids. Now, I’m all for this type of altruism, but sometimes I get bothered when people begin to get self-righteous about what they’re doing, especially when they start calling out other people on the basis of misguided logic. This section from the article caught my eye. I’ll go through it in pieces.

Although neither Theo nor Paul view the foundation as a political entity — ”It’s hard to be against helping disadvantaged kids,” Theo says — both brothers acknowledge they are frustrated that programs for children are shortchanged as professional athletes and front-office executives are paid millions for their games.

I couldn’t agree more. I would give a lot of money to any organization that could find new methods to identify and remedy child abuse: economic, physical, and mental. It’s a real problem, and one that’s so hard to correct due to privacy considerations that we all like.

”For me,” says Paul, ”I get angry when I think about the amount of money that’s going to players or is being generated by the clubs. There are very few athletes who do as much as they should in the community.”

So, it’s the athletes’ faults for not giving back to the community? How about all of the millions of fans who spend their money watching sports instead of helping the disadvantaged? Isn’t this where the money comes from? As best I can tell, professional athletes are some of the most generous people I have ever heard of. Maybe the question should be: “why do fans pay my brother’s salary when there is so much suffering in the world?” That is a good question, and I ask a similar question to myself quite often. I feel no guilt enjoying life to some degree, and so should all people. I think sports generate a lot of happiness for people and that’s a good thing. And I feel good knowing that players and owners seem to be generous with their fortunes.

Theo agrees, and even suggests the government might someday want to regulate professional sports.

”Not to offend any libertarians out there,” he says, ”but it’s not outrageous that 50 years from now the government could regulate sports, and basically cap player and front-office salaries and redistribute some of that money to, say, teachers.”

The call for regulation of sports to redistribute wealth in this area is just, bizarre. Why should sports be taxed any different that other types of income? Just because it’s large and visible? That’s a politician’s mentality. And then give it to teachers? Don’t get me started. If we’re going to start taxing leisure let’s eliminate subsidies to sports activities as well as parks, museums, and libraries. The statement “not to offend libertarians” offends me more than his following statement that is supposed to offend this “little-L” libertarian. By it’s nature that statement is opposed to libertarian principles. Don’t apologize for it, just say it. I’m a big boy, and I’ll be happy to disagree without having my feelings trampled on.

With that, Theo tugs on the bill of his baseball cap and takes a deep breath.

”I spend a lot of time thinking about what the hell’s wrong with America, and what the hell’s wrong with the world, and sometimes that results in misguided political discussions,” he says. ”But I don’t think people want to tune in to their local TV station and see their GM talking about much besides baseball.”

As they hustle to get A Foundation to Be Named Later off the ground, the brothers say they are keeping it simple: no highly paid help and no elaborate office space. Whatever they raise during the year, combined with Theo’s personal contribution, will be given entirely to the agencies.

They’re going to start out without highly paid help? Look, if you’re going to help people, hire the best; and, the best don’t come cheap. Giving out money to the right people is actually quite difficult work. Theo, you should know that. The same principles that apply in the players market apply in the philanthropy job-market as well.

I would also like to add, that I commend what the Epstein brothers are doing. And I whole-heartedly support it. Their hearts are in the right place.

Just my two-cents. Rant over.

100,000 Visits…Thanks

Sabernomics just passed the 100,000 “visits” mark today. I just want to thank all of you for reading. This is a heck of a lot of fun.