THE BOOK--Playing The Percentages In Baseball

Most Pitch F/X charts that I’ve seen are presented from the catcher’s viewpoint.  I didn’t think this was a live issue.

Tango - the default values for pitch location and spin deflection are from the catchers point of view, so that’s what pretty much everyone uses.  The only person I know who has adjusted them to be from the pitchers point of view is Mike Fast.

Everything should be from home plate looking out.

Has there been any word on the timetable for Hitf/x?

Nick/2, that’s probably true.  Emphasis on has.  I think that was over two years ago.

If baseball was shown on TV from the catcher’s perspective, I’d agree.  But given that we watch every pitch on TV from the pitcher’s perspective, albeit a little offset, I think this is just going to widen the gap between stats-inclined folks and non-stats-inclined fans.

Also, as a note to people writing pitch f/x articles… even if every one of you does it from the catcher’s perspective - PLEASE put a note below the first graph or image that states such.  I’ve seen a bunch of recent articles that don’t specify; while most of the writers probably know that catcher perspective is the “standard”, I’d bet 90% of readers don’t know that.

Rally/4, my understanding is that it’s up and running and has been since roughly April 2009.  The data is not being made public, however.

Everything should be from home plate looking out.

I don’t see why this should necessarily be the case.  I think Tango is right that having a convention is helpful in many cases.  But surely there are some cases where it is not helpful.

In thinking further about my response to Nick/2, I remembered that I have done some work from a third viewpoint, that of the batter from the batter’s box, that I believe to be among the most important and revealing work that I have done.

In addition, I believe it was Greg Rybarczyk who presented at the 09 PITCHf/x summit about reference frames in analyzing fielding data.  He had some very good thoughts about why the fielder’s reference frame might be valuable for some purposes.

It depends on what you’re doing with the data what reference frame you want to use.  If you’re trying to communicate about typical pitch location and spin deflection information to a mass audience, the catcher’s view makes a lot of sense.  If you’re trying to teach a pitcher about what he is doing, that same view may not be the best tool.

When I mean “standard”, and I say “Given that the choice for the PITCHf/x charts is rather arbitrary”, I am only discussing those situations where you are making an arbitrary choice in standard cases.

Obviously, in a more specialized discussion, and the angular aspect of seeing the home plate in a 3-D kind of way from the batter’s actual visual perspective demands a different viewpoint than the standard 2-D homeplate vantage point.

And yes, if the focus is specifically on other facets, then yes, a different viewpoint is fine.

I was only talking about when making an arbitrary choice, one where you can just as well go one way or the other, then you may as well follow a standard form.

This is a bit like when I said we should choose 0 degrees as being up the middle.  Arbitrarily, you can choose anything to be 0, and then everything is offset from that.  Standardizing to some relevant scale helps, and that’s all I am talking about here.

If there is going to be a standard, it might as well be the catcher’s perspective since that’s the data that PitchFX feeds us. On the other hand, I do enjoy Mike Fast’s approach when reading, since that is how the game is broadcast on television (when I’m watching MLB At Bat, I swing the perspective around to see it like they show it on TV).

That said, I’m not sure it’s a big whether there is a standard, so long as we heed Mike/6’s request that we label the chart.