Wow, great article Eric

Isn't the assumption being made that every batter begins to "pick up" the ball at the moment when it leaves any pitcher's hand (or a fixed small fraction of a second before or after)? It strikes me that this could vary among pitchers and batters as would the "perceived" velocities.

Great stuff, Eric. Glad to see some follow up on this issue after KG's post from the other week re velocity. And I'd love to see how this data shakes out on a pitcher like Tim Lincecum. Presumably his long stride compensates for his diminutive height and results in what might even be a closer (to home)-than-average release point, which -- when added to his already well above average radar gun readings -- goes far to explain his dominance.

Heath Hell has a huge add? He's not short but he's not CY. Is it something specific to him or is the Padres' mound somehow factoring in?

This is a really excellent finding, but somewhat disheartening given how much case-by-case work needs to be put in to calculate these values. It seems like perceived velocities might provide better correlations with observed results.

Now if only PitchF/X would grab this release data as well...

Eric Seidman for baseball czar!

Will pitcher height being factored in? A 91mph from a tall pitcher like Chris Young should have a sharper downward plane than a shorter pitcher, making their pitches "appear" more flat.

Just found one slight issue - the Padres game I was given was a bit off that day as all of the Padres and Angels pitchers had lower velocities on average than their seasonal lines. If all of them did, then it leads me to believe that Young and Bell still posted their quoted perceived velocities but that the deltas should go from 6.7 and 5.2 to more like 3.7 and 2.2, which makes a bit more sense. All of the other pitchers results stand.

Have you looked at data from pitchers throwing from the windup vs. the stretch? Could there be differences in the release point that could explain some anomalies (such as why some pitchers seem to perform better with runners on)?

Great article. I imagine that the next level of this, with the "attention zone" of the hitter, will be affected by whether a hitter is a pull hitter or can send balls to the opposite field. Ultimately, seeing the matchup of perceived velocity versus attention zone becomes a scalpel for a field manager seeking to optimize his lineup, compared to the butterknife that is the Lefty/Righty splits that exist today.

Tremendous research, Eric.

Does something like runs per 100 fastballs correlate better with perceived velocity instead of the Pitch F/X measured velocity? It's probably impossible to say given just 9 pitchers, but it might be worth a peak just to encourage you to measure more pitchers.

It doesn't sound like just using height as a proxy for explaining the difference between actual and perceived velocity will work. Any idea why the 6'5" Verlander has a negative difference between perceived and actual velocity given that he's taller than average?

Define "Fastball", i.e. two seam,cross-seam.etc .
Paul

I agree that this is tremedous, Eric.

As the data collection burden for this project is huge, I wonder if it might be worth the effort to see if a shorthand proxy might be available. Intuitively, it would seem that having two pieces of data, length of stride and arm length (sleeve length) might correlate well to the data. Just a thought.

What would be fun someday - is to backtrack and see if we can figure out any teams that are doing something like this. We know teams have private research. We also know that some teams are much better than others at finding effective relievers off the 'scrapheap' what would be intresting to know is if there a pitching staff out there that scores consistently better on these number.

It could be random chance, could be they have been doing this arleady...

Eric, I wonder if something went wrong in your calculations. By looking at still images, I find that most pitchers, Chris Young included, release the ball roughly in line with their plant foot. A pitcher's stride length is typically about his height or a little less.

In the case of Chris Young, his stride is possibly a little longer than his height, but not much. Take 60.5 feet and subtract 7 feet, and you get a release point around y=53 feet for Chris Young and more like y=55 feet for the typical pitcher. I don't think it's physically possible for Young to be releasing the ball inside of y=50 feet.

According to Dr. Nathan, the plane has less to do with it than I thought. So the likely issue with Young deals with the system being off for that series, and the new results from his games will be used in further studies on here. It'll likely produce a delta of 3-3.5 mph instead of 6. However, as we'll discss next week, location could make it appear +6 mph.

From Dr. Nathan:

"I used to do a simple demo for my introductory courses. I would fire a steel marble horizontally from the top of a table. Simultaneously, I would release another steel marble from the same height with zero velocity. The two marbles hit the floor at the same time. In both cases, the initial vertical velocity was the same (0) and the height
above the floor was the same. They experienced exactly the same motion y(t) in the vertical direction."