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the colonel per pitch/fX

a while ago over at Brew Crew Ball, a poster named dixieflatline presented some pitch/FX charts parsing out the velocity and movement on the pitches of the brewer starters, game by game. here’s a link to one of these posts, re dave bush; there are others if you hunt for them. very cool stuff. it turns out that dixieflatline is none other than josh kalk, creator of the world’s best publicly available pitch/FX data warehouse. right before i went on vacation, i asked josh if he would create such a chart for me on todd wellemeyer; i was curious to see if the chart showed a significant difference in the movement of his pitches --- specifically, his slider --- pre- and post-elbow. we’ve heard numerous times that welley’s slider isn’t biting anymore, and i wanted to see if that lack of bite could be quantified via pitch/FX. josh generously honored my request, preparing charts not only of todd’s slider but also his fastball. with wellemeyer slated to pitch tonight, i thought i would roll out the material today.

the charts arrived last week, while i was away from the blog, so they don’t include welley’s start vs the brew crew last thursday; the last start shown here is wellemeyer’s 6.1-inning, 5-run outing vs the padres on july 19, which he won. let’s begin with the chart of welley’s fastball:

first of all, the gray vertical line at day 160 corresponds to the initial manifestation of the elbow problem, in washington on june 5. everything to the left of that line (including the june 5 start) happened before the injury, and everything to the right of the line happened afterward (ie, all starts from june 13 forward).

look next at the black dots, the center row in the chart --- those represent the velocity of todd’s fastball. the mph scale is on the left-hand side of the chart; todd has averaged 92 to 93 on his fastball most of the season. right after the injury, his velocity increased into the 94-95 mph range for a few starts --- presumably because the extra rest put a little spring back into his arm.

now refer to the red dots, the bottom row on the chart; those show side-to-side movement. the averages are all below 0, which means his fastball runs in on a right-handed hitter; positive numbers break away from a righty, in on a lefty. note how smooth the line appears to be before the injury; with one exception (the may 9 start vs milwaukee, near day 130), the midpoints are very consistent from one start to the next. now look at the line since his injury ---- very inconsistent. one day he’s really busting ‘em inside, but the next day the same pitch stays 2 inches further out over the plate --- maybe far enough out there to get hammered. the erratic plot on the red dots post-elbow suggest a pitcher groping to locate his fastball --- a guy who can’t be sure from game to game where the pitch is going to go.

the blue dots at the top of the chart represent elevation: the higher the dot, the more the pitches stay up in the zone. (they’re labeled "vertical movement" on josh’s charts, but i’ll quibble with that terminology because it suggests that a pitch might break either up or down; in truth all pitches break down, it’s just that some break down more than others.) there’s been just a slight change there since the injury, a slight decrease in the elevation of the pitch --- nothing too drastic, but you can see it. this seems at odds with the velocity data --- i would expect the pitch elevation to increase with increased velocity, but apparently the opposite has happened. in any case, i don’t think it’s significant --- the change is small, and it has remained consistent, so presumably welley would be able to adjust to it. the most meaningful thing i see on the fastball chart is the unmooring of the side-side break on his fastball --- i think that illustrates a loss of command and an inability to locate pitches with snap, which are usually the problems associated with a tender elbow.

ok, let’s move on to the slider:

there’s not a whole lot to see ---- the average side-to-side movement (red dots) hasn’t changed much, pre- and post-elbow; ditto the average elevation (blue dots). and the average velocity on the slider (black dots) increased right after the injury, thanks to the extra days off. i had thought we might see a dramatic change, but there isn't one at first glance.

but the dots only represent the averages ---- the midpoint for each start. let’s look at the range, which is represented by the vertical lines sticking out the top and bottom of each dot. just to take an example, in welley’s second start of the year his slider velocity (the black dot) ranged from a low of about 81.5 miles per hour to a high of about 87. that’s a wide range, ie a high degree of variation or a lack of consistency. notice how the ranges on all three rows ---- velocity, side-side movement, and elevation --- tighten up after day 120 or so, right up until the injury. that corresponds roughly to the month of may, when todd was named nl pitcher of the month. the short range lines indicate that he was getting nearly identical movement on the pitch every time he threw it --- very consistent. after the injury, the range lines on all three rows go slack; from pitch to pitch his slider just hasn’t been as reliable in any respect (movement, break, or elevation). the velocity on the slider has been particularly sloppy since the injury --- the high-low ranges have been about 5 mph per game, and the midpoints (ie, the dots themselves) have bounced around quite a bit --- he was averaging nearly 88 mph on the pitch in his july 6 start vs the cubs, but less than 84 mph two starts later vs the padres on july 19. to the extent that welly has lost command of the slider, it’s most evident in the velocity row.

while these charts are illustrative, they don’t tell the whole story. there’s a critical element missing ---- location. if you throw a so-so slider on the outside corner, you might get a groundball to short; throw another slider with identical break and velocity but locate it right over the plate or put it belt high, and you’re going to get a different outcome. these charts won’t capture that kind of thing. but they do tell us something about pitch location, because when a guy starts to get inconsistent movement --- as wellemeyer has with both of his main pitches --- he’s going to miss spots.

thanks very much to josh kalk for taking the time to do this. if you haven’t browsed his pitch/FX data before, you really should.

a few items:

  • yesterday’s various statements re the cardinal closer perfectly encapsulated the situation. first thing in the morning, i proclaimed kyle mcclellan to be the best man for the job. later in the day, la russa --- impudently usurping my authority --- announced that the 9th inning still belonged to ryan franklin. a few hours after that, dave duncan repealed that executive order and declared that izzy has won his old job back --- he’s closing. and during the fsn midwest broadcast last night, john mozeliak said that adam wainwright might close some games when he returns from his injury. that about sums it up, eh? . . . .
  • tyler green got promoted to memphis --- big news for a former first-rounder who has struggled mightily. he was chosen at #30 in the 2005 draft, two slots after colby rasmus, but it has been a rough go for the kid --- didn’t hit in class A in 2006, didn’t hit in double A in 2007. he returned to double A again this year and started slowly, hitting .178 in april and .278 in may; but since june 1 he’s hit .305 and slugged .520 with 9 homers in 200 at-bats; his k rate is still high and his walk rate is abysmal, but if the guy is gonna have a career the cards have to challenge him. his MLE slash lines for the season are still only .206 / .253 / .329, so it’s not as if this is gi-normous news; but the cardinals need a shortstop, he can field the position, and he’s showing improvement at the plate. keep your fingers crossed. greene led off for memphis last night in his debut and went 1 for 5. he becomes the 6th player from the 2005 draft to reach triple A; 3 of those players (garcia boggs and stavinoha) already have played in st louis, and 2 others (rasmus and bryan anderson) are almost certain to make it.
  • another late-blooming 2005 draftee, 3d-rounder daryl jones, got moved up to springfield after posting an .876 ops at palm beach, a notorious pitchers haven. by my count, no fewer than 17 players from the 2005 draft have reached double A or higher, and i might be missing one or two; any of you draft experts out there know if that’s a high number for one draft? sure sounds high to me.