More on Halladay’s Curve “Evolution”

It’s a hot topic these days, Roy Halladay’s velocity. The facts and figures do point to a change in Halladay’s pitch speed, though whether that’s a cause for concern or evidence of a pitcher evolving and adapting to his age is a bit less certain.

Leaving that portion of the discussion aside, let’s continue the volley of examinations on this topic with an entry by David Hale on Delaware Online earlier Wednesday with a closer look at Halladay over 2011 and the first month of 2012. One table Hale has put together near the end of his post is Doc’s curveball rate by month in 2011, and the rise in usage is starkly evident. From 12.5 percent in April to more than double that with 28.7 percent in September, according to Texas Leaguers’ Pitch f/x data.

Naturally, then, my first thought was about effectiveness; as Halladay’s use of the bender increased, did it stay consistently effective at keeping hitters off-balance and off the bases? To examine this, I’ll be using the data provided by TruMedia to stay consistent, but the percentages only differ very slightly from those featured in Hale’s table.

The numbers I’m paying specific attention to, besides the usage rate, are how opponents
fared against it (triple slash stats and wOBA), how many swinging strikes it incurred and
how frequently it induced ground balls, all keys to any pitcher’s success. In summary, it looks something like this:

CB Total CB% AVG OBP SLG wOBA Whiff% GB%
April ’11 85 686 .124 .148 .179 .148 .155 30.8 56.3
May ’11 95 694 .137 .174 .167 .174 .150 50.0 50.0
June ’11 79 542 .146 .111 .111 .167 .119 43.2 50.0
July ’11 78 507 .154 .000 .000 .000 .000 42.4 60.0
Aug ’11 108 528 .205 .206 .229 .206 .201 36.0 36.8
Sept ’11 144 509 .283 .172 .242 .310 .237 50.8 44.4
April ’12 98 429 .228 .174 .240 .217 .215 31.0 58.8

The curve was supremely effective in smaller doses early in the season, limiting opposing
hitters to minuscule slash stats and wOBAs (including that nice, round zero in July), and
even as its usage increased, it stayed effective. Its effectiveness was diminished somewhat, but when you’re talking about wOBAs in the low .200s instead of mid-.100s, it’s a bit more difficult to complain or stress.

Though it went unnoticed in 2010, Halladay’s first year in Philadelphia, a similar trend occurred. By month in percentages, starting April, Doc’s 2010 curve usage was 14.3, 14.7, 14.3, 20.5, 21.6 and 17. That year, of course, Halladay walked away with a Cy Young Award, and 2011 saw him finish runner-up. Hey, if it ain’t broke…

Halladay will, in all likelihood, make one additional start this month, so the final row’s
numbers are destined to change, although it seems safe to assume that the ones in the
middle and right will stay plenty pleasing to the eye. And, if history is any indicator, Halladay and Carlos Ruiz will continue to fashion this deadly breaking ball more as the season progresses.

Leave a Reply



  1. Billy

    April 25, 2012 04:49 PM

    Great piece, Paul. Good to see you posting more frequently. This is the kinda stuff Crashburn needs more of.

  2. Tom G

    April 25, 2012 05:29 PM

    I’m leaning towards the “no big deal” school of thought as well, but the one thing that does trouble me is the decrease in strikeout rate.

  3. Josh G

    April 25, 2012 05:38 PM

    Very insightful.

    @Tom G
    You realize that the difference between Halladay’s career K rate and the 30 innings he has pitched this season amounts to 3 missing strikeouts? So if you (like me) are comfortable calling last start fluky bad on the strike zone (never seen that from Doc in his career), or if you are just willing to wait another 2 or 3 starts, I’m pretty confidant the strikeouts will be there.

  4. Tom G

    April 25, 2012 08:00 PM

    You know, after I left that comment, it occured to me that the strikeouts might not be that far off. Here’s an instance where the counting stats are (temporarily) more useful than the rate stats. Thanks Josh.

  5. Fatalotti

    April 25, 2012 09:35 PM

    Halladay has 4 starts this year. His strikeout rate is low, but sometimes great pitchers go through stretches where they just don’t strike out many batters.

    Remember Lee’s amazing June last year, where he gave up 1 ER over 5 starts, and pitched three shutouts in a row? Consider his line over his last 4 starts:

    35 IP, 1 ER, 0.26 ERA, 19 SO, 4.89 SO/9

    I wouldn’t be worried about Halladay right now.

  6. Pat

    April 26, 2012 12:10 AM

    Nice article, Paul.

  7. Phillie697

    April 26, 2012 03:10 PM

    Of ALL the bad things people can talk about with this Phillies team, why are we focusing on Halladay?

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