简短概要：
Pitch f/x系统显示主审的好坏球判决这七年来年年进步
证据也说主审的好球带比以前更大，而且他们还会型塑心目中的好球带
所以打者跟投手赛前必须知道这个主审的口味有多大多怪
现在有越来越多的声音要求用机器人主审取代人肉主审
但是主审也在进步，他们的错误率比15-20年前更少
赛后他们还会立刻接到一份通知告诉你今天漏了哪几颗好球、判了那些坏球为好球
图一：http://li.tl/v/uO9n
这张图显示整体素质是进步的，但是好的还是很好，烂的还是很烂。Tim Welke是被数据认
定为最烂的主审，Barksdale则是最好的主审。Barksdale平均每场能比平均水准的主审多
判决出五颗正确的好球，Tim Welke则比平均低五颗左右。
图二：http://li.tl/v/uO9e
好球带以内的好球筛检率显著提升，坏球的筛检率没有太大的波动
虽然Lance Barksdale在好坏球判断上面很强，但是不代表他整体的判决能力够好。好坏
球只是一部分，熟知比赛规则、守备判断、如何处理突发状况也都是主审的重要课题。而
现实上，在季后赛这类紧绷的场合所派出的裁判组合并不一定是采用好球带判断精确做挑
选。比如去年的美联冠军系列赛，这场比赛派出一口气出动精确度排名第70,71,76的裁判
(而排行榜总共只有79名裁判)。
Dusty Dellinger knows how difficult it is to be an umpire. “There’s an old
saying that they expect you to be perfect from day one and get better,” the
former Major League Baseball official said over the phone. As the director of
Minor League Baseball Umpire Development and the Minor League Baseball Umpire
Training Academy, he knows how elusive perfection can be.
Correctly calling 140 pitches flying 90-plus mph and breaking six inches or
more is a near-impossible standard. And when mistakes are made, players and
managers aren’t bashful. Jonathan Papelbon said D.J. Reyburn should “go
back to Triple A” after a confrontation over balls and strikes. Joe Girardi
complained about inconsistency. Larry Andersen did too after he retired,
labeling the men behind the plate arrogant. You don’t have to look too hard
for more examples.
That’s led plenty of people to wonder when robots will come for the umps’
jobs. But lost amid those blue-sky dreams is what’s happened to the way we
judge the blue behind the plate. Technology has changed how we can evaluate
umps. It shows that umps are getting better, that there’s a significant gap
between the best and worst, and that the best umps aren’t working the
biggest games.
After every game, umpires receive a report from the league office that
informs them about their accuracy, their correct calls, and the ones they
missed. Pitchers, hitters and fans have near-instant access to information on
an umpire’s accuracy, too. The chart below shows the accuracy rates for
calling balls and strikes for each ump since 2008, when MLB installed the
PITCHf/x tracking system in every stadium.
Umps are getting better, and they’re also remarkably consistent. An ump who
makes more accurate calls in one year will likely do the same the next; an
ump who misses more calls in a given season will likely be as bad the next.
Umpire accuracy is more steady than a player’s batting average or a pitcher’
s ERA, and as consistent as OPS (on-base plus slugging) and wins above
replacement.
To see how this works, look at the performance of Lance Barksdale and Tim
Welke. While they both follow the league’s general trend of increased
accuracy — more about that later — they have, respectively, been one of the
best and one of the worst umpires over the past seven years.
The difference between Barksdale and a league average ump is about five
correct calls per game; the difference between Barksdale and the league’s
worst umpire is closer to 10 calls a game. On average, that’s about one
judgment call per inning that a good ump is getting right and a bad ump is
getting wrong. That might not sound like much, but if once every six outs a
batter gets another swing after a third strike that wasn’t or a pitcher
strikes a hitter out on a pitch that’s actually a ball, you can start to see
the impact.
Given their differences, umps develop reputations. Near the end of infielder
Mark DeRosa’s 16-year career, he knew what to expect from the umpire calling
balls and strikes. “You gain knowledge over the course of being in the big
leagues for the course of a couple of seasons,” he said. “You understand
which umpires are a little bit wider in their zone, who are a little bit more
north-south, who’s going to force the pitcher to come tight.”
Before games, he and his teammates would even talk about what they could
expect during the game: “A comment would be passed back and forth, whether
we should be pulling the trigger tonight or ‘this guy is normally a hitter’
s umpire and likes to force the pitcher to come back over the plate, so let’
s be a little bit more picky with what you’re going to swing at.’ ”
An umpire who understands what calls he is missing is an ump who can improve.
“It was amazing how my perspective of the strike zone changed when I got
this technology,” Dellinger said. “I thought pitches were on the plate,
until you get that data back. You see that some of those pitches were not on
the plate. It wasn’t something that was done intentionally. It was just your
perception of the strike zone. I was able to quickly make adjustments based
on having that information, which was huge to me.”
Seeing the data, however, can make fans less charitable. “They see a pitch
that is out of the box, and they think, ‘Aw, he’s a bad umpire,’ ”
Dellinger said. “I’m thinking, ‘You should have seen it 15 or 20 years
ago.’ ”
He’s right — ump accuracy has improved since 2008. But it has been on only
one type of pitch: strikes.
While umps call balls no differently than they did seven years ago, they’re
accurately gauging strikes at much higher rates. This distinction is so large
that Brian Mills, a professor of tourism, recreation and sports management at
the University of Florida, cites the increasing size of the strike zone as
accounting for about half of the league’s 50-point drop in OPS since 2008.
In other words, steroid testing isn’t the only change responsible for MLB’s
drop in offensive output. It’s also more called strikes.
While the league and the umpires association have access to data showing that
specific umps tend to be better at calling balls and strikes, it does not
appear that they use this information to reward those who are the most
accurate with choice assignments, like the All-Star Game or the postseason.2
According to Peter Woodfork, senior vice president of baseball operations,
balls and strikes play a role, but don’t write Lance Barksdale’s name into
your World Series scorecard just yet. “Once you meet a standard, you’re in
the mix,” Woodfork said, likening the selection process to that of the NCAA
tournament. Assignments are doled out using a mix of analytics and judgment:
“Balls and strikes is taken into account along with field work, rules,
instant replay and handling situations. Professionalism also factors into
grading umpires. The plate work may carry more weight in the evaluation, but
they are all important.”
If plate work is important, it hasn’t shown in playoff assignments.
According to numbers from BaseballSavant.com, umps who were No. 70, 71 and 76
in the accuracy rankings (out of 79) called balls and strikes in the ALCS
last year, with only one of the top 10 umps receiving a league championship
series or World Series spot. And this more exhaustive look at umps also finds
that postseason spots do not appear to be linked to regular-season
performance.
“Like any other profession, you can go up and go down, but the consistency
over time often helps,” Woodfork said. “We don’t ignore what you’ve done
in the past, but that year carries the most weight.” If that’s true, expect
our old friend Barksdale to receive a high-profile opportunity, as his 90
percent accuracy rate through July 1 is far and away the best single-season
number in our data.
But while decisions on postseason spots won’t come for several weeks, MLB
has already had one opportunity to reward an umpire for past performance,
getting to pick a home plate umpire for July’s All-Star Game.
It chose Tim Welke — the same Tim Welke who has consistently had one of the
league’s worst rankings since 2008.