• Are We Ever Biased Towards Umpire Bias?

    There is no question that umpires have biases. The question is whether we want them or not.


    A couple of years ago I reported on a book that I was reading titled Scorecasting by Tobias J Moskowitz and L. Jon Weerthem. This writeup is going to copy a lot of that story. The book is similar to the book Freakonomics, except that it focuses exclusively on sports. If you have an iPad or iPhone, you can download the first chapter for free Ė and just that much changed forever how I watch baseball.


    The chapter is about a bias that umpires have because they are, with the possible exception of Joe West, human. And humans are far more willing to forgive an error of omission over an error of commission. That is, we are more willing to forgive an error caused by doing nothing over an error caused by doing something. And thus humans are for more willing to commit an error of omission over an error of commission, because it gets us into less trouble. Iíll give an example from the book:


    ďIn a well-known psychological experiment, the subjects were posed the following question: Imagine there have been several epidemics of a certain kind of flu that everyone contracts and that can be fatal to children under three years of age. About 10 out of every 10,000 children with this flu will die from it. A vaccine for the flu, which eliminates the change of getting it, causes death in 5 or every 10,000 children. Would you vaccinate your child?Ē


    Most parents opted to NOT to vaccinate their child, despite it halving the chances of their child dying. The thought of doing something to the child which would cause his or her death was worse than the though of doing nothing and doubling the chances of death. The same bias is statistically apparent in umpires when it comes to calling balls and strikes and now I canít help but notice it.


    In 2007, mlb.com installed the pitch f/x equipment in all the ballparks, providing data on 2 million pitches, including 1.15 million called pitches. Suddenly we could see from data how accurate umpires were in calling balls and strikes, and whether there are any circumstances that made them less accurate. It turns out there are.


    A ball that is in the strike zone is called accurately by an umpire 80.2% of the time. But that number dives if there are two strikes on the batter (and it isnít a full count). Then, a ball in the strike zone is called a strike just 61.3% of the time. Heís almost twice as likely to mistakenly count a strike as a ball. Again, donít forget Ė we KNOW that these are really strikes from the f/x data.


    The same thing happens the other way on pitches outside the strike zone on three-ball counts, though itís not quite so drastic. A pitch outside the strike zone is called a ball 87.8% of the time, but if there are three balls (and itís not a full count) itís only called a ball 84% of the time.


    The reason? Because calling strike three or ball four ends the at-bat. Itís active Ė it affects the game far more than giving the batter and pitcher another pitch to resolve the at-bat themselves. The incentive is toward the error of omission rather than that of commission.


    Incidentally, this is most apparent on borderline pitches. Over all counts, a borderline is called a strike 49.9% of the time Ė almost literally a coin flip. But with a 2-strike count (again not a full count) itís called a strike just 38.2% of the time. And with a three ball count, itís called a strike 60% of the time. The percentages become even more extreme on 3-0 and 0-2 counts.


    This may be a bias that we, as fans, want to reward. For the first time, I thought about whether or not I really want to take that kind of call out of an umpireís hands. Donít we want someone who prompts the batter and pitcher to resolve their conflicts themselves? Even if it might not be a perfectly accurate call.

    This article was originally published in blog: Are We Ever Biased Towards Umpire Bias? started by John Bonnes
    Comments 29 Comments
    1. Teflon's Avatar
      Teflon -
      How would it be any different than a ref in the NFL deciding when and where to enforce the out-of-bounds line based on the score of the game or hockey waiving offsides calls for teams that are trailing? Geez Louise. Imagine a crisply played baseball game where at-bats were actually resolved based on the true merit of the pitch being thrown. I would pay more to go to those kinds of games.
    1. Thrylos's Avatar
      Thrylos -
      yeah
      Umpire Bias has no place in sports. These guys act like the sport owes them. They can replace them with cameras these days and have a more fair and better played game. Get a ballboy behind Home Plate to throw in balls.
    1. Oxtung's Avatar
      Oxtung -
      Quote Originally Posted by John Bonnes View Post
      Donít we want someone who prompts the batter and pitcher to resolve their conflicts themselves?
      You're overlooking a very large piece of the puzzle. The batter and pitcher DID resolve the play. The pitcher threw the ball and the batter made the decision to not swing. That pitch should be called accurately exactly because the play WAS resolved by the batter and pitcher. This is the exact same problem that occurs at the end of many professional basketball games (with the same argument of "let the players decide the outcome"). The players DID decide the outcome with their actions. If it is a ball or strike with the first pitch then it's a ball or strike with the last. To me the real question here is ... how much emphasis should be given to the pitch f/x by the umpires? Should they try to adjust their calls now that there is a feedback mechanism? Can you adjust your ball/strike calls in those situations just by knowing your biased? That would be an interesting experiment!
    1. jorgenswest's Avatar
      jorgenswest -
      Is data about individual umpires public or at least available to teams?

      Perhaps teams might adjust how aggressive they are at the plate based on the home plate umpire.
    1. USAFChief's Avatar
      USAFChief -
      A few points:

      1. I don't think it's necessarily accurate to say that we KNOW a given pitch was a ball or strike based on pitch f/x. We only KNOW where pitch f/x measured it. There's no way to measure whether pitch f/x is accurate, other than blind trust. It might be quite accurate. Then again, it might not. How would we know? Not to mention, as far as I know the top and bottom of the pitch f/x strike zone is still human input guesswork, because that changes with every hitter.

      2. Umpires are given pitch f/x data after every game they call behind the plate.

      3. Teams have kept "books" on umpires for a long long time. Each individual umpires tendencies are known to hitters and pitchers.
    1. James Richter's Avatar
      James Richter -
      Quote Originally Posted by Oxtung View Post
      You're overlooking a very large piece of the puzzle. The batter and pitcher DID resolve the play. The pitcher threw the ball and the batter made the decision to not swing. That pitch should be called accurately exactly because the play WAS resolved by the batter and pitcher.
      Correct. This is why Red Sox/Yankees games take so blasted long to play: everybody in both lineups knows the ump doesn't want to call them out on a borderline pitch. If there has to be bias, it would be better if the umps erred on the side of calling close pitches strikes. Hitters would take more swings earlier in the count, there'd be more balls in play, fewer pitches thrown, and faster games. Maybe we could get back to 11-man pitching staffs!
    1. mike wants wins's Avatar
      mike wants wins -
      Agree with the above, it is an active choice not to swing or to swing. A pitch should always be called for where it was thrown, regardless of the situation. It is the only truly fair way to play a game, by the rules. Otherwise, it is not a fair contest. I 100 percent hate umpire and referee bias.
    1. mike wants wins's Avatar
      mike wants wins -
      To add to my thoughts....bias is one of the reasons I don't watch the NBA. Bias is one reason I stopped watching Braves baseball back in the day. How can we ever know that Jordan was the best basketball player ever, if he got every call? Call the game the same way, for everyone, all the time during a game. That's the only fair way to play a game. If two people are playing against each other, but one is playing by rules that give her an advantage, are they even playing the same game? I have no idea why anyone would like bias. Take the "let the players decide" idiocy of the NFL interference rules. By not calling interference, because you want the play to rule, you are actually not doing so. If it is interference, it is interference. By not calling the penalty, you are not letting the playerd decide the game, you are letting one player play by different rules, and making it an unfair contest. It's logical laziness to say you are letting the players decide the outcome of that play.

      Have I mentioned how much I hate unfair application of rules in sports and other competitions? There is no good argument for the bad application of rules. None.*

      *in professional or other high level competitions, we aren't talking about little kids here.....
    1. JB_Iowa's Avatar
      JB_Iowa -
      While my first reaction would be that I hate umpire bias, my second thought is: "I love the game."

      Given that what John is describing is unintentional umpire bias (i.e. human nature), I have to think that it has ALWAYS been present in the way that games have been umped.

      Trying to rid the game of this unintentional bias could have a significant impact on the game -- and quite frankly, I'm not sure we'd be happy with the results.

      Educate umpires. Keep monitoring performance. Make gradual improvements.

      Just because we have technology to make changes doesn't necessarily mean that it would be an improvement. And, as pointed out above, it doesn't necessarily mean that the technology is totally accurate either.
    1. mike wants wins's Avatar
      mike wants wins -
      I would love it if strikes were strike, and balls were balls. A totally fair contest between pitcher and hitter. That would be cool. As jb points out, making the change is not so easy.....and change always has unintended consequences.
    1. Curt's Avatar
      Curt -
      We want the game called as accurately and consistently as possible. Surely we can all agree on that? I am not an advocate of instant replay nor of human umpires being replaced by technology. I am in favor of using technology to help the human umpires improve their performance, in this case, using the f/x technology to remove this bias.
    1. YourHouseIsMyHouse's Avatar
      YourHouseIsMyHouse -
      Very interesting piece John. I really thought about the vaccination question before I read on and decided that vaccination would be the best idea. I would really like to see more commission than omission from home plate. I think borderline strikes should always be called, because the hitter has to know that it's close enough to where he could be caught looking. The 80% to 60% gap because of an 0-2 count is definitely not surprising and frustrating to say the least. Pitchers get squeezed in those situations a lot! Umpires need to stop taking pity upon batters and call the game the way it was designed to. You'd think they'd want to get out as quickly as possible, but that is never the case!
    1. sln477's Avatar
      sln477 -
      I was working on an article that addresses this issue, but in a different light. Do umpires "create" great pitchers & relegate others to average or poor pitchers. I have often wondered if umps have biases towards certain clubs/coaching staffs than others. It is human nature to "favor" someone who is favorable to you, while it is also human nature to be "less favorable" to those that may treat you less favorably; even though we are not inclined to admit as much. We have watch countless hours of baseball & probably all agree that we have wondered why pitcher "X" is getting the calls, while pitcher "Z" is not receiving the same calls. It can then be said, that pitcher "Z" now has to be more precise, thus possibly making more mistakes, leading to poorer performances. I can't help but think that some, not all, umpires have this bias towards certain clubs/managers. Any thoughts??
    1. Boom Boom's Avatar
      Boom Boom -
      Quote Originally Posted by sln477 View Post
      I was working on an article that addresses this issue, but in a different light. Do umpires "create" great pitchers & relegate others to average or poor pitchers. I have often wondered if umps have biases towards certain clubs/coaching staffs than others. It is human nature to "favor" someone who is favorable to you, while it is also human nature to be "less favorable" to those that may treat you less favorably; even though we are not inclined to admit as much. We have watch countless hours of baseball & probably all agree that we have wondered why pitcher "X" is getting the calls, while pitcher "Z" is not receiving the same calls. It can then be said, that pitcher "Z" now has to be more precise, thus possibly making more mistakes, leading to poorer performances. I can't help but think that some, not all, umpires have this bias towards certain clubs/managers. Any thoughts??
      I would imagine that this has more to do with the individual pitchers than the teams. Pitchers with long track records of success will often get the benefit of the doubt on close pitches, while green rookies and journeymen will not. It may also have something to do with the catchers and their ability to frame a pitch. If a catcher has to move his glove much to catch a pitch, even if the pitch is caught in the strike zone, the umpire may have a more difficult time making the correct call because of the extra variable of the moving target.
    1. James Richter's Avatar
      James Richter -
      Quote Originally Posted by Boom Boom View Post
      I would imagine that this has more to do with the individual pitchers than the teams. Pitchers with long track records of success will often get the benefit of the doubt on close pitches, while green rookies and journeymen will not.
      How about the PJ Walters vs. Jose Bautista AB last weekend? Borderline 2-strike pitch from a marginal big leaguer to a former MVP goes the MVP's way. The AB continues and Bautista hits a HR that decides the game. If Roy Halladay had thrown the very same pitch to Trevor Plouffe, do you think the ump would have called it differently? Should he have?
    1. Boom Boom's Avatar
      Boom Boom -
      Quote Originally Posted by James Richter View Post
      How about the PJ Walters vs. Jose Bautista AB last weekend? Borderline 2-strike pitch from a marginal big leaguer to a former MVP goes the MVP's way. The AB continues and Bautista hits a HR that decides the game. If Roy Halladay had thrown the very same pitch to Trevor Plouffe, do you think the ump would have called it differently? Should he have?
      Yes, as established pitchers often get the borderline calls, the inverse is also true. An unproven starter isn't going to get as many calls when he's pitching to a big-time hitter. I don't think that should be the case, but it is what it is.

      When Joe Mauer takes a close pitch he's more likely to get the ball call than Drew Butera. If the umpire doesn't have a great look at the pitch he might defer to a hitter that he thinks has a good eye.

      Come to think of it, that may be an interesting research project. What % of borderline pitches go the way of the hitter when the batter is Derek Jeter, for example, as opposed to Trevor Plouffe?
    1. snepp's Avatar
      snepp -
      Here's an article that I really liked on the topic.

      The Compassionate Umpire

    1. dwintheiser's Avatar
      dwintheiser -
      So the results here seem to support the idea that umpires, following years of fan and official comment that games should be decided on the field rather than by an umpire's call, are reluctant to make calls that could decide games?

      Sounds like we're getting exactly what we asked for.
    1. powrwrap's Avatar
      powrwrap -
      Quote Originally Posted by thrylos98 View Post
      yeah
      Umpire Bias has no place in sports. These guys act like the sport owes them. They can replace them with cameras these days and have a more fair and better played game. Get a ballboy behind Home Plate to throw in balls.
      I hope you are using sarcasm here.
    1. John Bonnes's Avatar
      John Bonnes -
      Regarding umpires & how they react to certain pitchers, I've wondered about certain pitches. Say a guy has a curveball that starts in the one but darts out of it late. If that pitcher can't get that pitch called a strike, that might be a significant handicap. Or if it is, he could be nearly unhittable.

      Here's another question: should the zone be different for right-handed & left-handed batters? Must it be symmetrical?
©2014 TwinsCentric, LLC. All Rights Reserved.
Interested in advertising with Twins Daily? Click here.