More photos » by Gene J. Puskar - AP

Milwaukee Brewers' closer Trevor Hoffman ponders the sheer awesomeness of his changeup. (AP Photo/Gene J. Puskar)

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Most of our readers are are familiar with the concept of linear weights for evaluating pitchers and hitters. The basic concept is, say if a batter hits a double or a pitcher gives up a double, there is an average runs gained for the team by that double-- if it's a leadoff double, a 2 out double, or a bases-loaded double. On the other side, a strikeout always reduces the average amount of runs scored. If you add up all the events, give them each a run value compared to average and divide them by the number of chances, you wind up with a number of runs contributed by the player to the team above or below average.

Fangraphs has unveiled a new feature that takes evaluating pitchers to a new level-- pitch type linear weights. The method is to determine the run expectancy of an inning before a pitch is thrown, and then find the run expectancy of the inning after the pitch is thrown. Then all of the changes in run values get added up to create one super cumulative total for runs above or below average. So when Manny Parra gives up a home run on a splitter, he gets dropped whatever the average home run was worth minus what was expected to be scored before the pitch was thrown. When Manny strikes someone out with a splitter, he gets a few tenths of a run added on. And finally, keep in mind that these are context-neutral but not luck adjusted like tRA-- a groundball double down the line is the same as a booming double to a gap. This is also not just a measure of stuff, but of control-- a strike reduces expected runs, and a ball adds expected runs. Every pitch is taken into account-- ball, strike, hit, homer, out, whatever it is.

So enough with the methodology, let us see if there is any interesting trends to be found with Brewers pitchers. Are there any pitches that should be thrown more or less?

I'll start out with Manny Parra, everybody's favorite intellectual. I wrote a short story about Parra's fastball and why, at that point, I felt he should throw his fastball less and breaking pitches more. The numbers tend to back that idea up, as for some reason Parra's fastball is not as effective as his off-speed pitches. Last year on fastballs, Parra was -1.55 runs/100 fastballs, and this year he is -1.48/100 fastballs. It is important to note that fastballs will generally be below average because they are the most frequently thrown ("establish the fastball"), so when compared to breaking balls, they will come out worse. But Parra's fastball is quite unproductive.

Parra's rates for his slider (which he does not throw very often, only about 1-2% of the time), his curve, and his splitter have remained about the same. The curve has been about average both years, and the slider and splitter slightly above average. The change from this year to last has been the increased hittability of his changeup-- +9 runs cumulatively last season, and already -5 this year. That corresponds with Manny flipping the frequency of the curve and the change-- he threw the curve 17% of the time in 08 compared to 13% in 09, and he's thrown the change 20% of the time this year compared to 13% last season. The team has stressed that Manny is throwing his changeup more, but maybe it's time to go back to switching out some changes for curves again. We can only hope that would make the changeup more effective. But the good news for Manny is that the pitches except for the change haven't drastically changed effectiveness, so even though his FIP has jumped nearly a full run to 5, his stuff is good enough to get back to where he was if the change becomes effective again.

I'll move on to Dave Bush now, who should make another interesting case because of all the tampering he does with his repitoire. Dave's fastball has fluctuated; he was about -1 runs/100 pitches with his fastball in 07, +1 runs/100 pitches in 08, and he's sitting on an average fastball right now. That's probably just fluctuation that we can't draw too many conclusions from. Bush has a pretty solid repitoire of fastball, slider, cutter, curve, and change right now and he's mixing them all very well and throwing his straight or two seam fastball less than 50% of the time. This year, three pitches have resulted in about average (or the same run expectency before and after the pitch). The changeup has gotten hit hard, and the cutter has been his most effective pitch. I don't see anything in particular that I would suggest that Bush change.

Meanwhile, Yovani Gallardo is really good. All four of his pitches cumulatively have saved the Brewers runs this year. His best pitch this year on average has been the changeup, saving 2.94 (!) runs per 100 pitches, and he's throwing it more than it has before. His fastball, curveball, and slider have all saved 1 run for every 100 pitches.

Jeff Suppan, on the other hand... the Brewers lose run expectancy with every pitch except the changeup (surprising, because I detailed how the 3mph gap between fastball and change was not nearly enough earlier this year). His fastball comes in at a near-Parra -1.35/ 100 pitches, his curve is at -1.5/ 100 pitches, and the slider is -.5/100. The change adds 1.5 runs per 100, though I would not be surprised if some changeups are classified as fastballs in the fangraphs algorithm. I made a suggestion for Parra, and I will make one for Suppan as well: retirement. Well, that's an exxageration of course, but he has to mix his pitches more and locate better to have success in the future, because the defense isn't going to be help him out as much the rest of the way. 

Braden Looper has thrown fastballs, splitters, and sliders with the Brewers. 30% of his pitches are splitters, and it's a good thing-- he's +2.42/100 pitches with the split and about -1.5/100 with both the fastball and slider. Nothing shocking there, though I hope Looper starts to pitch better soon-- he's been the beneficiary of luck and defense as much as Suppan has, posting a very high home run allowed rate and walking a full batter more per nine innings that he did a year ago on the way to a 5.62 FIP, over a run beyond most projections. We'll hope he gets stronger with the fastball and slider as the year goes on. Both pitches were much better the bast two years, very close to average.

Finally, a few highlights from the bullpen:

Hoffman's fastball and slider take about 3 runs from the opponents expectation every 100 pitches, and his changeup is only at, oh, +7. Not to bad for the old guy.

Mark DiFelice's cutter gives us about +2.5 runs. It's an awfully good pitch, especially when you consider that he throws it more than 80% of the time.

All four of Carlos Villanueva's pitches are above average. He is a rare (and really good) type of a reliever. He's striking out 9 per 9 out of the pen the last two years.

Todd Coffey's slider: +4 per 100 pitches, best of his career, and his fastball has jumped from -1 to +1 per 100 pitches. He's found something with that pitch.

Mitch Stetter's slider is filthy. He throws it 60% of the time or more and it adds +2.5 runs per 100 pitches to the Brewers chances.

Well now wasn't that fun, and soon, we can do the reverse and look at the Brewer hitters against types of pitches. If you have any questions on the stat and methodology, do not be afraid to ask.