The Hardball Times

Batted ball insanity

by Harry Pavlidis
July 21, 2009

Fresh from the PITCHf/x Summit, I mean BASEBALLf/x Summit, my mind is full of questions about batted balls and fielder positions. While HITf/x and BASEBALLf/x are not ready for prime time (HITf/x may be close), I'm thrilled to have a little bit of data on batted balls. By combining April's HITf/x data and Matt Thomas' photogrammetry, I can present a few examples of issues we'll someday be able to explore in every game. I hope reading this article will be at least half as fun as it was putting it together.

Photo what?


Thomas specializes in using photographs to take measurements of physical space. That's his day job. On some nights, you'll find Thomas in the press box at Busch III working as a stringer. Thomas uses a camera to capture stills of the action, creating a record of locations, and timings, of movement on the field. Thomas happened to be working at Busch two nights in April that were also captured by HITf/x. He was kind enough to send me the data from April 24 and 26, Cubs at Cardinals, in all their glory.

The data


Thomas provided some interesting information for each batted ball, measuring the point of contact, passing through the infield (when applicable) and reaching a fielder (or sometimes the ground or a wall). The specific data points include:

HITf/x provides:

Gameday adds in:

Seeing how Thomas, as the stringer, feeds Gameday, there should be plenty of overlap. There is, and I'm going to use a limited set of factors, but I should point out I found one play that was coded differently in Gameday than in Thomas' data file.

My question is simple, as hinted at in the title: Will two batted balls with similar or nearly identical initial characteristics result in different outcomes? Will they be described differently within Gameday? What other factors seem to be associated with these discrepancies? In other words, can the same thing happen twice and either end up differently or be described differently? If so, what other piece of information helps us explain that subjective difference?

To attack this question, I used HITf/x data (SOB, Launch and Spray) to pick similar batted balls. Gameday provided the outcome, and Thomas' data (along with HITf/x and Gameday itself) are used to explore/explain the differences.

The plays

I found at least four pairs of interest, but I'm limited this discussion to two of them.

The first pair of hits I picked differ in one important way—speed.

Ball 1
SOB 98.3
Horiz. half-way between second and third, a little closer to third (114.9 in the raw HITf/x data)
Vert. -13.1 degrees

Ball 2
SOB 73.0
Horiz. same as above, within .1 degree, Thomas' found "theta" to be within 1 degree for the two hits, also (114.8)
Vert. -13.6, slightly lower than above

Here we have two hard-hit grounders. One was hit very hard. They went to almost the identical spot, but ended up with very different results.

Ball 1
"Alfonso Soriano reaches on fielding error by shortstop Khalil Greene."

Ball 2
"Reed Johnson singles on a sharp ground ball to left fielder Chris Duncan. Geovany Soto to 2nd."

First, the "sharp" notation appears on ball two but not ball one. I believe Gameday doesn't allow for the sharp/normal/soft distinction on errors. Still, given the slower speed, I found it curious. Second, while both plays occurred with one out, it was ball two that came with a runner on first.

While Greene did field the first ball cleanly, it was smashed probably a little bit to his right. The second ball, despite being hit slower, made it through for a single. Why? I would guess Greene was pulled over towards second base, cheating for the double play. According to Thomas, Greene reached (or was reached by) ball one 1 in 1.6 seconds. Ball two passed the infield in 1.5 seconds. What I don't know is the nature of the hop, as that could matter if this ball was just on the edge of Greene's range.

The next pair had a lot more in common.

Ball 3
SOB 78.3
Horiz. about the same as 1 and 2, just a little more toward second base (114)
Vert. 25 degrees

Ball 4
SOB 75.0
Horiz. 4 degrees closer to second base (108.2)
Vert. 29.7 degrees

So, ball three was hit a little bit harder, a little more towards the gap, and on a lower trajectory (at least initially). So, what happened?

Ball 3
"Alfonso Soriano lines out to left fielder Colby Rasmus."

Ball 4
"Mike Fontenot flies out to left fielder Colby Rasmus. "

Have we really found the line between a fly ball and a line drive? Were these both fliners in BIS lingo? What else was different?

So, we have a pulled line drive caught below the waist and an opposite field fly caught chin-high. Otherwise, they're very much alike. I wonder if positioning could explain why Rasmus seemingly arrives later to ball three (perhaps the .17 seconds of time difference is accurate).

I realize I've raised more questions than I've answered—to address the two pairs discussed above, a review of the video tape and some details on player positioning could provide simple answers to the questions raised. But there are other plays I need to review, such as:

Other ideas? Leave 'em in the comments.

Summary


While the data for this study were a lucky break, we're months, not years, away from this being a regular thing. Even with limited data, this baseball nerd was well entertained.



References and Resources
Thanks to Sportivision for the HITf/x data and Matt Thomas for putting his photogrammetry data together for me.

Harry Pavlidis admits he has a baseball problem. He is the founder of Pitch Info LLC, His pitch classifications power the player cards at Brooksbaseball.net. Feedback, questions and comments are appreciated - Email harrypav@gmail.com and Twitter @harrypav

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