Why Are Hitters Swinging At More Bad Pitches?

Today, instead of telling a story using numbers, I’ll let the numbers do all the storytelling. I think in this case that they have something to say. The table below comes from Jamie Moyer’s plate discipline stats. While I am interested in Moyer in general, it’s not his stats here that jumped out at me. Instead it’s the major league averages, which appear in the orange-colored rows.

Click for larger size

The first two columns certainly stand out. While overall swing percentage isn’t too far off from previous years, both O-Swing% and Z-Swing% have moved moved a bit. This year hitters are swinging at 28 percent of pitches outside the zone, a nearly three point jump from 2009. The number does move around a bit, dipping as low as 16.6 percent in 2004. On the other side, hitters are swinging at fewer pitches inside the zone as last year, 63.8 percent against 66 percent from last year. That number appears to increase to some degree all the way back to 2002. We’re also seeing much more contact on pitches outside the zone.

I’m obviously wondering why we’re seeing this discrepancy. Why are hitters swinging at pitches outside the zone more frequently than in the past? This seems like a good question to crowdsource. I’ll present a couple of ideas, and you guys can build on them. It’s certainly something I’d like to hear more about.

1, This is just an early season thing. They say hitters get better as the weather warms. Maybe that has as much to do with them getting into a groove — hitters are getting closer to the 250 PA mark — as it does the weather.

2. It’s just part of the natural cycles of the game. Hitters were more patient earlier in the decade. Maybe now they’re starting to be more aggressive.

3. Related to No. 2, and perhaps a bit to No. 4, pitchers are exploiting a weakness and are making hitters chase more.

4. Pitchers are just hurling nastier stuff. Hitters are having a hard time adjusting to tougher breaking and off-speed pitches. I’m not sure how you could go about proving this one, so it’s probably an afterthought, if that.

5. The criteria for pitches inside and outside the zone has changed.

6. Just blame the umps.

Again, I’m not really sure if this is something that we’ll see continue all season, or if No. 1 more fully explains it. I’m also sure that there are many, many more possible reasons. I’d like to hear them, though.

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Joe also writes about the Yankees at River Ave. Blues.

43 Responses to “Why Are Hitters Swinging At More Bad Pitches?”

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  1. Millsy says:

    Perhaps the focus on Walks being more valuable these days, players are watching more pitches. Pitchers might know this, and throw them more strikes, which they still take while waiting for their pitch to drive. From there, batters are watching more strikes and therefore getting into less hitters’ counts than before, being forced to swing at 0-2, 1-2, 2-2 pitches that are near the edge or outside of the zone to protect?

    I don’t know, just trying to write up a story of some kind. Maybe the ‘wait for yours’ mantra has gone too far as to get hitters behind in counts more often? I’m sure someone could look at the number of these types of counts (and when the outside the zone swinging) is taking place.

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    • Millsy says:

      Expanding on the above: it may not be that the ‘wait for yours mantra’ has been taken too far. Perhaps the approach being taken is still optimal (rather than “too far”), but just results in these events more often.

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      • Joe R says:

        To be fair, I clearly remember I was at my worst as a hitter when I wasn’t being aggressive (back when I played).

        I mean it was partly due to a fear of the strikeout, which we all know now is stupid, but some guys just struggle when down in the count. I’d rather a guy never walk vs. never hit.

        /waits for the attack due to being overly general.

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      • Millsy says:

        Looking closer, despite the fact that they’re swinging at these things, the Swinging Strike % has been decreasing, while the O-Contact and Z-Contact % has been increasing. So while they’re swinging at them more, they’re making contact. Could that indicate more defensiveness from being deeper in the count on average? Like I said, I don’t know.

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      • Jeff Francoeur says:

        I, too, am not at my best when I’m not being aggressive. A .270 OBP is good, right?

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    • philosofool says:

      If this were a good explanation, I think we would see a rise in f-strike rates.

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      • Millsy says:

        Good point, philosofool. Maybe hitters are better at making contact with the first strikes they DO swing at? (or do f-strikes also include pitches swung at?)

        Perhaps hitters sit on first-pitch fastball strikes? So the change in pitchers’ counts are coming more so after the first pitch? Like I said, just throwing things out there.

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  2. dcs says:

    #5 seems the most likely to me.

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  3. Joe R says:

    #2 and #5 are the logical choices to me.

    Fat guys who walk aren’t getting the playing time they did in the 00’s. Teams aren’t going to put a debacle in the field for a marginal gain on offense.

    For that, we see guys like Adrian Beltre being lauded in free agency, when it 2006 people were calling for his head on account of not walking.

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  4. ingeindahouse says:

    ive been wondering this for a while great topic for an article

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  5. LarryinLA says:

    I’d add that the O-contact% is also way up. So, either these out of the zone pitches are easier to make contact with (i.e. the zone has changed) or hitters are taking a very different approach. Or, #1. Even if it is #1, though, it might still be worth looking into what’s different about pitches in April/May than July/August.

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  6. strictbusiness14 says:

    Did you happen to notice the corresponding increase in O-Contact %? O-Swing goes from 18.1 to 28.0 and O-Contact goes from 47.4 to 66.3.

    Maybe players are just getting better at hitting pitches outside the strike zone, lessening the need (in their own minds) to lay off those pitches.

    Or maybe it’s becoming easier to hit pitches outside the strike zone for some reason (e.g. a larger percentage of pitches thrown outside the strike zone are closer to the strike zone than in the past).

    Just something to consider, I think.

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  7. Matt says:

    3. and 4. I like the least out of your possible theories. If it were pitchers exploiting weaknesses with their extra nasty stuff, I don’t think we would be seeing such an increase in contact on pitches outside the zone (which is a bigger jump that the increase in O-swing%).

    The only new idea I can come up with is the trend towards younger, more athletic players, and away from older veterans. I don’t recall seeing (at least not recently) stats for the average age/experience of major leaguers this year, but if those numbers have dropped, maybe it’s a result of a bunch of younger guys with better hand-eye coordination but less plate discipline.
    Or in other words, it’s the Pablo Sandoval effect.

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  8. etsuke says:

    It could also be that there is a greater focus on run prevention (fielding especially), and therefore hitters are worse. Worse hitters have worse plate discipline. I think it is a combination of factors, with normal yearly variation being one of them.

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  9. intricatenick says:

    What’s the fouled off strike % look like through the years? Hitters could be concentrating on fouling off more pitches out of the zone to stretch pitch counts and make pitchers work more.

    You could have more foul balls and it wouldn’t necessarily show up in any of your other hitting stats – but it would in terms of O-Swing%.

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  10. Andrew says:

    Could one player’s plate discipline be so terrible that it would skew stats for the entire league? Because Adam Jones might just be that player.

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  11. Gabriel says:

    Perhaps there is a combination of 5 and 6 — has the strike zone itself changed at all over the last several years? If it were growing, batters would have to swing more often and pitchers would have more opportunities to fool batters.

    Does Pitch/FX data tell us if the strike zone has grown at all?

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  12. Mike Savino says:

    Could the possibility of stricter pitch counts and less spectacular flameouts of young pitchers be partly responsible for the “nastiness” of pitches? If this were still 2002, King Felix and Zack Grienke both would probably have been allowed to throw 140 pitches in a game. And they’d both have probably had Tommy John. I just wonder if a) pitch counts have actually kept young pitchers healthier and b) what that has done to league average hitting as hitters don’t get to feast on quad-A or worse pitchers.

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    • wobatus says:

      There were only 69 games above 125 pitches in 2002. I don’t think Greinke and Hernandez would have been going to 140 by then.

      True, there were only 14 in 2007. Games above 125 dropped. But the real big drop was after 2000.


      I think etsuke may have it mostly right.

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  13. The Usual SusBeck says:

    Increased use of LOOGYs and ROOGYs put batters in a position where they can’t see the ball out of the pitcher’s hand as well more often?

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  14. Gary York says:

    I don’t know if the official or nonofficial strike zone has changed over the past several years. However, I watch plenty of games on the Fox Sports Network and the zone that they flash up after questionable pitches, time after time, shows that the umpires are calling more inside and outside pitches strikes. The high and low calls are generally okay. So I’d go with the consensus and say 5.

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  15. hello says:

    The only logical explanation is because players have stopped injecting steroids directly into their eyeballs. I’m told that’s the only reason Barry Bonds was any good.

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  16. UZR is a Joke says:

    There was a change this offseason that allows pitchers to go to their mouth while on the mound. They previously could do it off the mound, but wanted to speed up the game. They have to wipe before going to the ball, but I wonder if this is having an impact on late movement.

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  17. philosofool says:

    For what it’s worth, the rate at which the pitcher has the platoon advantage is 1.5% higher this season than last season.

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  18. vivaelpujols says:

    I’m guessing it’s all #5. O-Swing was at 16.6% in 2004, which is insane and impossible, meaning that BIS or FanGraphs has changed the way they calculated the stat at least once. I’m guessing that’s what’s happening here as O-Swing remained constant from 2007-2009.

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    • Well, I can tell you for sure that we did not change our calculation of the strike zone. BIS has not notified us of any change in the coordinates of the way they map strike zone so we’re calculating it exactly the same way as we’ve always been.

      It’s possible BIS changed their criteria slightly for what is inside and outside the strike zone leading to some slight changes in mapping, but this is precisely why we show the averages.

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      • vivaelpujols says:

        I didn’t mean to accuse FanGraphs of doing anything wrong here. Can you tell me how the stat is calculated? Does BIS just present you the raw data or do they calculate the stat themselves and send that to you?

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      • We get raw data with pitch location coordinates and we’ve been told the 4 coordinates that make up the corners of the strike zone. Anything in that box is in the strike zone and outside is not. That’s really all we’re doing.

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  19. DavidCEisen says:

    In 2002, pitchers threw 55% of their pitches in the strike zone. This year they have thrown 47% in the zone. The general trend has been that through time fewer pitches are being thrown in the strike zone.

    In 2002, batters swung at 46.5% of pitches seen. This year they have swung at 44.9% of them. Swing% has remained fairly constant since 2002, though.

    Contact% has also trended slightly higher since 2002–increasing from 78.5% to 81.1%. This disproves #4 and, I think, #3, as hitters aren’t getting ‘fooled’ by pitches.

    #1 doesn’t make sense either, since there is a noticeable trend in the data that spring time baseball can’t explain.

    There a few other possible explanations for this:

    The strike zone has shrunk and batters are swinging at exactly the same pitches. This explains the increase is OSwing% and OContact%, but the stability in Contact% and Swing%.

    Pitchers are pitching more outside the strike zone, but hitters want to swing the bat just as often. So hitters have adapted by swinging at close balls that are hittable. I don’t know if I think this is likely, since 2002 was the peak of OBP, so pitchers trying to pitch more out of the zone doesn’t make intuitive sense–not that intuitive sense means anything.

    #2, in which hitters are more aggressive makes sense. Pitchers are throwing fewer pitches in the zone, because hitters are swinging at and making contact with pitches outside the zone that normally would have been taken for a ball in 2002. This prevents pitchers from even having the opportunity to throw in the zone. Pitchers may have adapted to the OBP-centric approach that was becoming dominant by nibbling the corners and try to get close strike calls and batters responded by swinging at more close pitches, which is a nice Red Queen Hypothesis narrative–not that narratives are ever a good idea.

    Basically more data and research is needed–just don’t look at me.

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    • Devon F says:

      I agree with this, the corresponding drop in Zone % can’t be ignored. The sample size for zone % is much larger too, as more pitches are thrown than swung at, making me think that this is a definite trend.

      Youth is also more valued than it was years back, as is defense. Putting young and/or more defensively skilled players out there nowadays could increase the overall aggression numbers of the hitters at the plate. Instead of older veterans with good eyes, we have younger players who might be more vulnerable to chase a bad pitch. No data to support, but it’s a trend that could hold some merit.

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  20. Andy says:

    What about #7? The cameras determining the strike zone aren’t quite as accurate as we’re giving them credit for, but have been getting better over the years. This alone couldn’t explain the observed changes, but it’s at least worth considering as a factor.

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  21. Cork says:

    There are many that think the ban on amphetemines is having a much bigger impact on baseball than the ban on steroids. Supposedly hitters used amphetemines at a higher rate than pitchers whereas steroids were universal.

    Without the amphetemines, players are going to the plate with less focus. I could easily see that leading to less command of the strikezone.

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    • neuter_your_dogma says:

      No medical exceptions for “BADD” players? (baseball attention deficit disorder).

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  22. Rick says:

    I find it interesting that your eye went to the first two columns. During that same period, O-Contact% jumped from 47 to 66 and Z-Contact% went up slightly from 85 to 88.

    For me, the O-Contact% surge suggests 3 variables
    1) Hitters physical ability to make contact has improved substantially
    2) Hitters plate approach has changed such when they do swing at pitches out of the zone, they are swinging at more hittable pitches (proportionally speaking)
    3) Hittable pitches that were previously classified as in the zone are now being classified as out of the zone.

    For me, explanation #5 is the only that seems consistent with the across the board changes. Some portion of hittable pitches that were previously classified as in the zone are now be classified as out of the zone. The zone has shrunk.
    The Zone% decrease may be the clearest evidence of this. I find it hard to believe that pitchers have collectively changed their approach or lost the ability to throw strikes.

    However, I think we’re also seeing that hitters are becoming more generally selective, perhaps in response to the zone change. This would explain the decrease on swings in the zone as well the decrease in swinging strikes (which aligns almost exactly with the overall swing% decrease)/ contact rate.

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  23. isavage says:

    Looking at the current team stats, I’d have to say it’s nothing more than #5. Only the Braves at 24.6% are below last year’s average O-swing rate of 25.1%. The Red Sox have been second in the league the last 2 years in lowest O-swing %, but they’re still swinging at a rate this year (25.2%) that was slightly above last year’s league average rate. Pretty hard to believe that such an across the board change could occur in one year.

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    • Rich says:

      “The Red Sox have been second in the league the last 2 years in lowest O-swing %, but they’re still swinging at a rate this year (25.2%) that was slightly above last year’s league average rate. Pretty hard to believe that such an across the board change could occur in one year.”

      In the Red Sox case, the team has turned over pretty hard. Bay was pretty much replaced by Beltre as the offense goes, and thats a ton of walks lost, and most likely, a lot more swinging out of the zone.

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  24. pft says:

    Based on my observation the strike zone seems wider for most of umpires, in some cases ridiculously large (high and low seem ok). Once hitters realize the zone is enlarged early in the game, they start swinging at anything close as the game progresses. Of course, I don’t see enough games to be statistically significant.

    This would also explain the drop in offensive production in the AL, not to mention 3 perfect games (even if one will not go in the books as such) in 1/3 of a season. The rate of hitters called out looking has increased from 25% to 27% this year (AL).

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  25. Tim says:

    #5 for sure.

    We know Selig formed a committee to figure out how to shorten the games. This is their solution.

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  26. neuter_your_dogma says:

    Because Ryan Howard was paid 125M not to walk. Swing the bat, earn the bread – the agent’s mantra.

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