To say the least, P.J. Walters has been a controversial prospect around these parts. Views range Walters being the next great control pitcher to a soft-tosser with only a trick pitch that helped him dominate the lower minors and nothing more. We found a lot more about P.J. on Friday when he was thrown into the fire against the Cubs. While he struggled early, he settled in and made a pretty nice argument for his prospect status and beyond that, a full-time big league job.

Recently I have added pitch f/x graphing to my blogging repertoire and had planned on doing a breakdown on Walters, but I’m still rather green when it comes to the subject. So rather than hearing from me I brought in the heavy guns and asked pitch f/x guru Harry Pavlidis to help us take a closer look Walters. You probably know Harry from Beyond the Boxscore, THT and…ahem…Cubs f/x. Don’t worry, he’s not here to kick us while we’re down after a couple of gut-wrenching losses. Take it away, Harry —

Friday, in the midst of a Cubs/Cardinals series,  P.J. Walters made his major league debut. On the mound in Wrigley Field. Against Carlos Zambrano. Heady stuff.

Walters set the tone early, striking out Alfonso Soriano. With a couple 89 mph fastballs mixed in around some high-70s breaking and off-speed stuff, the game was on. Walters did get knocked around a little bit and only lasted four innings, but he gave the Cardinals reason to consider him for a rematch against the Cubs next weekend in St. Louis.

P.J. exceeded most expectations in terms of velocity, keeping his fastball right at or under 89 through his entire outing. His breaking stuff was as advertised – slow but nasty. You can see why his circle-change is sometimes called a screwball, because it dances like one. According to Walters himself, it’s a change-up. Whatever label you choose, it was impressive.

PITCHf/x Profile

Each of Walters’ 98 pitches were recorded by PITCHf/x on Friday. Using my own pitch classifications, I’m calling him a four-pitcher pitcher. I’m using a generic label for his fastball (FA) although I believe he threw maybe two or three four-seam fastballs, and the rest sinkers. I’ve already mention his change-up (CH) and for his breaking stuff, P.J. has a slider (SL) and a curveball (CU).

The probable sinker averaged an even 89 mph, with the bottom end of Walters’ speed spectrum being crowded with curves (72.4), sliders (78.2) and that change-up (76.4). One of the reasons P.J. gets so much sink on the change-up is simply the effects of gravity. You throw a ball that softly, nature has more time to act on that long, slow flight to home plate. Another reason it sinks is he drops his arm to throw it. [erik dropping in here: sorry for any shrinkage of the graphs. They were in the WordPress pool! Click on any of them to see in full view.]

The lower-left inset shows each pitch that went into the averages, the top-right inset is spin direction by speed by spin rate (bubble size). Those numbers are corrected for arm angle, so you’ll get less spread left-to-right (spin axis values) than you see in the main chart and lower inset. There is one change-up that does look awfully screwy, isn’t there?

About those release points … this graph is measured in feet, catcher’s view again. The inset, which is in the same scale, is the scatter plot of individual pitches. You can clearly see, in blue, the lower release slot for the change-ups. The fact that it is lower and wider indicates an arm angle change, not a shift in position on the rubber.

Putting that into motion, sort of, gives us three views of the ball’s flight. Top, side and catcher’s.

You can see the change in release points on the change-up in all three graphs. The ball simply comes out of a different spot. That may not serve P.J. well in the long nor short run.

You may have noticed the differences in average plate location, evident in the flight paths. Two on one edge of the plate, one on the other and one down the middle. Then there’s the high/low split, too. A closer look, starting with a pitch location scatter, may peel back another layer P.J.’s debut.

Again, catcher’s view, measured in feet. The zone is for reference purposes, but roughly reflects a typical zone as played (yes, two feet wide). You can see how well Walters kept the ball down and how those plate locations reflected in the flight paths came about. Walters was spreading his pitches around side-to-side, tending to keep things within the top and bottom of the strike zone.

Another way to look at pitch location is by “slice” or “layer”. Slices are horizontal position, from off the plate (Wide or Tight) to the middle 10 inches (Fat) or on the remaining 7 inches on either side (yes, again the two foot plate). Those parts we’ll call “Out” and “In”. Layers are the same concept, from High to Low being out of the zone, and Up, Middle and Down each being 1/3 of a hitter’s zone.

That last point is important, in two ways. First, the slices of the plate are not even proportions, while the layers of the hitter’s zone are. And the top/bottom is set individually to each hitter, based on their full history of PITCHf/x strike zone settings.

OK, enough explanation for, here are the graphs. More explanation right after ….

If you ignore the colors in the top chart, you’ve got his overall slices and layers. Each pitch is represented by a different color within the bar, so you can see how each pitch was thrown, and how often.

For example, Walters kept the ball mostly middle and down, in the zone. The slider, however, was shifted a layer down, as was the change-up. The fastballs were actually spread out across the entire zone.

The lower charts show, without reference to pitch type, locations by inning. Hence the 1-2-3-4. You can see P.J. had three less pitches around belt-high as the game went on, but there was some tendency to miss up more than down in the zone, especially in the second inning. Remember, we’re talking small samples.

Wrap-Up

Well, that’s a lot of info and explanation. What have we learned?

• Walters doesn’t throw hard, but hard enough considering the tail
  and sinking action
• 89 is plenty when you have three pitches in the 70s with different
  movement
• He drops down to throw the change-up
• Has pitches for either side of the plate
• Shows signs of having good command of the strike zone
• May actually be able to handle pressure

Thanks to Erik for letting a Cubs fan stop by. If TLR throws a rookie into the fire Sunday night, maybe I’ll even get invited back.

This entry was posted on Sunday, April 19th, 2009 at 1:27 pm and is filed under P.J. Walters, pitch fx. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.