August 29, 2005

From The Mailbag

Hit List, WXRL, King Felix, Injury Prediction, The Twins

by Baseball Prospectus

Hitting the Hit List

The Angels have a better record than the A's, a better record for the week against better opponents, and a better run differential for the season, yet you list the A's higher and have them going up. I know I am biased for the Angels but how do you explain your ranking without admitting bias?

--B.B.

B.B.,

Contrary to your belief, there is zero subjectivity on the Hit List. The rankings are done by equally weighting actual, first-, second-, and third-order winning percentages for the season to date as calculated in the Adjusted Standings.

The A's rose (trend arrow up) because despite their 1-5 record, the elements that determine their higher-order winning percentages didn't worsen as much as the teams around them. Particularly, they did well preventing runs as noted in the comment; that tends to have a positive effect on their Pythagorean calculations. The A's had a bad week, but the White Sox, who were above them, had a worse week, and the Braves and Angels, both below them, had weeks that were nothing to write home about either:

A's were outscored 22-17
White Sox were outscored 28-14
Angels outscored opponents 30-27
Braves were outscored 38-37

Also, while the Angels have a better actual run differential than the A's, once the park and other adjustments are applied, the A's differential is better. All told, the A's, Indians, and Angels are separated by .0027 percentage points in the Hit List Factor (the average of those four percentages above). That's about a third of a win at this point in the year. One run here or there might have been enough to reorder the three teams.

--Jay Jaffe

Figuring Felix

I was looking at the 'slide show' of Felix Hernandez in action--my God, what a pitcher!--and I'll hazard a guess about that mystery pitch he threw from time to time. Judging from the description of the way it breaks (falling off the table), I'll bet he's got a knuckle-curve like Mike Mussina and isn't telling anyone about it. Wonder what else he has in his repertoire?

--Zita Carno

Zita,

After talking to several people in the know, my suspicion that the pitch was a change-up appears to have been confirmed. It's rare to see a change act that way--almost like a splitter. But having watched Pedro Martinez up close for so many years, I can tell you that it can be done. And since Felix has to be considered one of the most talented young pitchers to come around since Pedro anyway, I'm willing to give him the benefit of the doubt.

--Jonah Keri

WXRL wonder

Hi there. Long time baseball fan and recent Baseball Prospectus subscriber here. Love the site and have found it quite useful, but have come across one nagging statistic that I can't seem to figure out, and was hoping you might be able to explain to me.

The stat is WXRL. I understand what the statistic is intended to show, but am a bit befuddled by how one gets there. Take Phillies reliever Aaron Fultz, for instance. By all conventional metrics, Fultz has been significantly more effective this year than in years past. If we compare it to his 2003 season in Texas, it seems no contest:

Year   IP    H    ERA    K   BB
2005   43   29   2.51   35   12
2003   67   75   5.21   53   27

Yet, despite what appears to be a significantly more effective 2005 season, Fultz's WXRL so far in 2005 is -.161, as compared to the +1.34 he posted in 2003. The only possible explanation I can imagine for this could be that he faced much tougher batters in '03 than in '05. This seems unlikely though, and I can't imagine it would account for the tremendous discrepancy in WXRL.

I am in the process of doing some serious number crunching to try and estimate the likely future value of different relief pitchers, and was planning on using WXRL as one of my chief measuring sticks of success. The seeming discrepancy I saw with regards to Fultz though, has given me pause, and I can't really move forward until I am able to understand it. If you happened to have a quick minute that you might be able to spare and explain what I'm missing here (i.e. what is driving the discrepancy between Fultz's conventional metrics and WXRL), I'd be very much in your debt.

--A.G.

A.G.,

WXRL is the change in expected runs due to the reliever's performance. As such, it matters very much the kinds of situations he comes to pitch in--and whether his good outings were in high or low leverage situations.

A simple example. A pitcher appears in two games. He gets lit up for 3 runs in one inning of work in game A, strikes out the side in game B.

Now consider two different game situations:

Situation 1: 1 run lead, bottom of the ninth. Assume win probability
upon entering is 80%.
Situation 2: Down by 12 runs, bottom of the 7th. Assume win
probability upon entering is 5%.

Combining the games and situations, there are two possibilities: A1,B2 or A2,B1.

A1: Blows a tight game, and his team loses. The reliever's win
expectation for this appearance is 0% - 80% = -0.800
B2: Pitches a perfect inning, but the game is pretty much
hopeless. Maybe the team has a 7% chance of coming back now. Win
expectation for this game is 7% - 5% = +0.020

The pitcher's combined WX for these two games is -0.800 + 0.020 = -0.780. Let's look at the other case:

A2: Pitcher shuts down the other team to preserve a clutch win. WX =
100% - 80% = +0.200
B1: Pitcher puts them further into an already deep hole. Suppose Win
probability drops to 4%. WX = 4% - 5% = -0.010

Pitcher's combined WX for the second case is +0.200 - 0.010 = +0.190.

A pitcher's performance in higher leverage situations will have a larger effect on his WX (and WXRL) than his performances in low leverage situations. Game A was very high leverage, Game B was very low leverage. And his performance in Game A pretty much determined his actual game value over that span.

WXRL is a way to assess past performance, usage, and game importance. But it is not independent of how and where a pitcher is used. A better measure for that would be Adjusted Runs Prevented (ARP), which takes into account only how a pitcher performed, not the leverage of the situation, but does consider inherited and bequeathed runners fairly in doing so. Hope that helps.

--Keith Woolner

Transaction Analysis: Soriano

The Twins just claimed Alfonso Soriano off of waivers. The initial reports indicate this is simply to keep him from getting traded to another divisional rival. But I have to admit I don't know enough about how the system works; what are the chances the Twins actually wind up with Soriano on their roster? (And I assume this would not mean they have to give up someone like Liriano?) Thanks.

--Adam Meier

Adam,

Well, the waivers were revocable, so it was dependent on Texas and Minnesota being able to work out a mutually agreeable deal, or the Rangers just letting Minnesota have him. Neither transpired, so you can consider this a successful block. The real question is who he was headed to, although I would suggest that it's more likely that he was being dealt to a rival for the wild card slot, and not to the Indians or White Sox.

--Chris Kahrl

UTK Special

Is there a correlation between number of days on DL from one year to the next? Is the correlation greater for pitchers than for hitters? I am wondering if there is any validity to terms such as 'injury prone' or 'slow healer.'

--D.C.

D.C.,

For individual players? No, not really. Where I look for "slow healer" is in days on DL over expected. Each injury has an average and range for how long it takes someone to come back and when someone exceeds it, I want to know why. Often, there's a reason--"sprained ankle" has degrees and its impossible for me to know. The lack of transparency is one of the reasons that injury stats will take so much longer to develop on the outside than it will to do as others have done with performance stats.

--Will Carroll

Bottom of the Ninth

I'm still kicking myself for not going to the pre-game at the King's Oven, but I wanted to see some batting practice at the stadium before the game started.

Anyway, I enjoyed your writeup, but it was also fairly disappointing to me. I know the big story is Felix, and that's going to trump everything else, but if this is the only Twins Game of the Week writeup, I feel like I got the short straw. There were plenty of things the Twins did in the game that seemed worth mentioning.

1) Batting Matthew LeCroy cleanup. He's been great against LHP, but against RHP, he's slugging .343. Batting him cleanup against RHP is offensive suicide. How about Jacque Jones and his .491 SLG vs. RHP?

2) Having Nick Punto in the game in the first place. Punto doesn't hit anything, but Luis Rodriguez has been hitting RHP well, with a line of .317/.386/.446. It doesn't seem that fluky either, as he generally hits the ball hard--I felt that his F7 last night was the hardest hit ball off Felix all night.

3) That the bunt by Lew Ford would've been good enough with almost anyone other than LeCroy running from second. (And that bunting wasn't all that bad of an idea, considering how painfully slow LeCroy is, runners on 1st and 2nd with no outs is the most favorable situation to bunt in, and Ford's not likely to give you anything more than a single against Felix, which still wouldn't score LeCroy.)

4) The bizarre decision to pinch-hit Luis Rodriguez for Ford instead of Punto. This definitely made the Twins weaker in the field, and may well have directly lead to Seattle's only run.

5) What's with no respect for Lohse? He's got an RA+ of 112 after the game, and he's been healthy all season. There's a lot of value in that. Enough, in fact, to make him 21st in VORP amongst AL starters. There are a lot of teams that could use Lohse as their 3rd best starter, and some where he would be their 2nd best starter.

6) Gardenhire trying to destroy the confidence of Jason Bartlett by pinch-hitting for him whenever possible. I felt Bartlett had the best at-bat against Felix of anyone the first time through the order, working him to a full count. Pinch hitting Mike Ryan at the end of the game was silly, and it was already too late to move Jones to CF to help the defense.

I don't know, maybe it seems silly for me to criticize you for not telling me things I already think I know, but it just would've been nice to see someone else point out that Gardenhire has been doing everything in his power to kill this team, or just hear more about my favorite team from an outsider's point of view.

--M.S.