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Robert Arthur 

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12-18

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6

Moonshot: In Search of Pedro Cerrano
by
Robert Arthur

12-03

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20

Moonshot: The Power of Projections
by
Robert Arthur

11-26

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8

Moonshot: A New View of Plate Discipline, Part 3
by
Robert Arthur

11-21

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8

Moonshot: A New View of Plate Discipline, Part 2
by
Robert Arthur

11-07

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9

Moonshot: The New Best Way to Measure Plate Discipline
by
Robert Arthur

10-29

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2

Moonshot: Do the Giants Beat the Heat?
by
Robert Arthur

10-22

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8

Moonshot: The Royals, the Strike Zone, and an October Surprise
by
Robert Arthur

10-15

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18

Moonshot: The Victims of a Bad Strike Zone
by
Robert Arthur

10-08

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7

Moonshot: Fastballs and the Collapsing A's, Part 2
by
Robert Arthur

10-02

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23

Moonshot: Fastballs and the Collapsing A's
by
Robert Arthur

09-19

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6

Moonshot: Detecting the Best Medicine
by
Robert Arthur

09-09

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0

BP Unfiltered: BP At Fox Sports: The Impact of the Evolving Strike Zone
by
Robert Arthur

09-09

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8

Moonshot: The Year In Zone Distance, and Next Year in Breakout Candidates
by
Robert Arthur

09-03

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18

Moonshot: Time vs. Pace
by
Robert Arthur

08-28

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12

Moonshot: On Regressing Defense
by
Robert Arthur

08-20

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38

Moonshot: The Analytic Value of the Crack of the Bat
by
Robert Arthur

08-12

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2

BP Unfiltered: Sveum's Unheard Guide to Fixing Royals' Offense
by
Robert Arthur

08-06

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10

Moonshot: Troy Tulowitzki and the Brittle Bones Hypotheses
by
Robert Arthur

07-30

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25

Moonshot: Separating the Phenoms Who'll Make It From Those Who Won't
by
Robert Arthur

07-22

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11

Moonshot: Accounting for Count
by
Robert Arthur

07-18

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3

BP Unfiltered: BP at Fox Sports: Anthony Rizzo and the Making of An All-Star
by
Robert Arthur

07-16

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5

Moonshot: The Matter of the Heart
by
Robert Arthur

07-08

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1

Moonshot: Survival of the Fittest: Position Players
by
Robert Arthur

07-01

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1

Moonshot: Survival of the Fittest: Pitchers
by
Robert Arthur

06-24

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21

Moonshot: Dale Sveum and the Royals Remedy
by
Robert Arthur

06-17

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5

Moonshot: Striking Distance
by
Robert Arthur

06-10

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4

Moonshot: Learning from Yasiel Puig's First Year
by
Robert Arthur

06-03

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5

Moonshot: What Makes Position Players Injury Prone?
by
Robert Arthur

05-21

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6

Moonshot: PITCHf/x and Batter Breakdowns
by
Robert Arthur

05-12

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10

Moonshot: Predicting Batter Breakouts with PITCHf/x
by
Robert Arthur

05-05

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7

Moonshot: The Winding Path of Albert Pujols, Via PITCHf/x
by
Robert Arthur

04-28

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19

Moonshot: How Quickly Do Team Results Stabilize?
by
Robert Arthur

04-23

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6

Moonshot: What PITCHf/x Can Tell Us About Batters
by
Robert Arthur

04-14

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8

Moonshot: Does April Velocity Last?
by
Robert Arthur

04-08

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10

Moonshot: Miguel Cabrera and the Bearable Heaviness of Being
by
Robert Arthur

04-01

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7

Moonshot: Cracking the Location Code
by
Robert Arthur

03-25

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5

Moonshot: Attrition Over Time
by
Robert Arthur

03-14

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16

Attrition By Position
by
Robert Arthur

03-12

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8

The Art and Science of Sequencing
by
Robert Arthur

02-06

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14

Baseball ProGUESTus: Entropy and the Eephus
by
Robert Arthur

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December 18, 2014 3:00 am

Moonshot: In Search of Pedro Cerrano

6

Robert Arthur

Looking for evidence of the 'fastball hitter'.

The “fastball hitter” is one of the oft-repeated archetypes in baseball. This is the notion of a hitter who can strike fastballs just fine, but struggles to deal with the unpredictability of a breaking ball. A simple search of Baseball Prospectus’ archives reveals 64 results for “fastball hitter”; Google, surveying the entirety of the internet, pulls down more than 10,000. Like many of baseball’s finest tropes, the fastball hitter has even been enshrined in cinema lore.

Beyond movie characters and conventional wisdom, it seems plausible that some batters might have more difficulty recognizing or mentally adjusting for the break of a curve, for instance. Curves and sliders, in particular, possess not only the capacity to slice through the air horizontally, but also are often said to create visual illusions in the mind of hitters.

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December 3, 2014 6:00 am

Moonshot: The Power of Projections

20

Robert Arthur

The error spectrum of projections shows the limitations of analysis, or the progress we can still make.

It’s around the time that projection engines are being tweaked, updated, and improved, in anticipation of the release of new predictions for the coming year. At Baseball Prospectus, Rob McQuown is hard at work ironing out the kinks for this year’s release of PECOTA. Given the present focus on predictions, the time is ripe for a retrospective look at how the projections fared last year.

There’s no better source for a large-scale comparison of projection algorithms than Will Larson’s Baseball Projection Project, which I will use for this article. Larson’s page houses the old predictions of as many different sources as he can get his hands on, including methods as diverse as Steamer, the Fan Projections a FanGraphs, and venerable old Marcel. It’s a rich storehouse of information concerning the ways in which we can fail to foresee baseball.

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Constructing a leaderboard that passes the smell test.

I’ve recently written about the role and value of plate discipline in hitting. I concluded the last article with the takeaway that plate discipline, while undoubtedly important in hitting, was not fully separable from the other attributes of a hitter. In searching for a complete per-pitch way of evaluating hitters, we have to account for the entire package of skills, because all of the skills interact with each other. So we have to go back to basics.

Despite being athletically impossible, hitting is theoretically simple. Every hitter is confronted on every pitch with a choice: to swing, or to take. A take is valuable when the pitch is likely to be a ball; depending on the count, you can get a walk, or at least advance the count in a favorable direction. If you swing here, you both lose the benefit of the called ball, and also risk whiffing on the pitch or making weak contact. On the other hand, when the pitch is thrown over the middle of the plate and is thus likely to be called a strike, the better choice is to do your best to make contact. If you take, you get a strike, and lose the opportunity of a hittable pitch.

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November 21, 2014 6:00 am

Moonshot: A New View of Plate Discipline, Part 2

8

Robert Arthur

Turning a smarter, better plate discipline measure into a leaderboard--and examining what it means.

Last week I wrote about how thinking about the zone in a probabilistic way could inform a better approach to plate discipline. In brief, I wrote that the zone as a discrete box above the plate does not exist. In its place, we can judge each pitch according to the probability that it will be called a strike, building into our estimate some of the factors which we know change the geometry of the zone. Examining plate discipline in this fashion proved illuminating, not to mention predictive of walk rates.

There’s a further step we can take with this probabilistic zone, which is to bring in linear weight information in order to judge the actions of each batter. In so doing, we can get an idea of the value of a hitter’s decision-making translated into the fundamental currency of baseball, runs.

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The problem with zone rates: There's no zone.

In the sortables section of Baseball Prospectus, there is a report called Batter Plate Discipline. If you’re trying to get a handle on how good hitters are at reacting to balls and strikes, this section contains measurements on such things as swing and contact rates. A natural way to divide such rates is based on the strike zone: A swing at a pitch inside the zone is a different event than at one outside the zone. A whiff on a pitch middle-middle is a disparate event from a whiff on a pitch way outside, so it makes sense to tabulate them in different columns. There is a problem with this dichotomy, however: There is no strike zone.

In the words of Michael Lopez (who borrowed in turn from Bobby Ojeda), the strike zone is a unicorn. By this I mean not that the strike zone does not exist at all, but rather that it does not exist in the way that Major League Baseball defines it. The rulebook definition is a rectangular solid hanging in space, with infinitesimally thin boundaries which, once touched, trigger strike calls.

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You've seen it in a hundred chyrons: The Giants do well against fastballs that come in faster than 95 mph. But the stat is nonsense. Is the idea behind it nonsense, too?

One of the statistics bandied about with great frequency in the World Series coverage has been the Giants' collective proficiency against the fastest of fastballs (typically defined as more than 95 mph). On several occasions, broadcasters have mentioned that the Giants hitters do well against these pitches, both as a team and with reference to particular individual players. The tenuous conclusion to be drawn from these statistics is that the Giants will continue to do well against the blistering heat, including those fastballs wielded by such prominent Royals as Yordano Ventura and the Reliever Triumvirate.

As many have noted, the stats as presented on the broadcast are terrible, for a bevy of reasons. We can start with batting average, which I probably don’t have to tell you is not a very good index of a hitter’s skill or outcomes. We’d like a better metric, ideally something that included the value of plate discipline (walks are valuable, too!).

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After months of moving downward, the October strike zone is suddenly rising.

Everybody’s been writing about the strike zone recently, and that’s for good reason. The strike zone is evolving, and for the first time in the history of baseball, we have the technology to directly record that evolution. Mostly, the bottom of the strike zone is dropping, and that plays some role in shaping the current pitching-dominated era (although exactly how much of a role is a matter of some debate).

What’s most astonishing about the strike zone’s changing definition is the rapidity with which we are witnessing the results. Year after year, the strike zone falls, and this year has been no exception. In this recent article, Jon Roegele chronicles the most dramatic drop in the bottom of the strike zone yet: In the last year, the zone’s real estate has increased by 16 square inches. But even without a rigorous statistical analysis of the zone, you could feel the impact of the strike zone’s accelerating fall in the numerous strikeout records which have been broken, and in the historic seasons of Clayton Kershaw and other pitchers.

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October 15, 2014 6:00 am

Moonshot: The Victims of a Bad Strike Zone

18

Robert Arthur

When umpires don't call balls and strikes the way we expect them to, who suffers?

One of the emerging storylines of the postseason so far has been inconsistency in the strike zone. That’s not unique to this postseason, of course; every year sees its share of poor calls, and the effect of those calls is magnified when so much is on the line. Whereas a missed strike may be objectionable in the regular season, it can (at worst) alter the outcome of one game out of 162. Missed calls in the postseason, on the other hand, can end seasons.

As a result, every bad call an umpire makes is scrutinized to a much greater degree. When an umpire’s zone is off—poorly defined, or merely inconsistent—whole legions of fans can flood the internet with vitriol. Generally, an umpire who’s doing a bad job of calling balls and strikes won’t favor the fortunes of one team or the other. But it is frustrating, as a fan, to see a beleaguered slugger’s bat taken out of the game on a borderline call, as happened to Matt Kemp recently.

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October 8, 2014 6:01 am

Moonshot: Fastballs and the Collapsing A's, Part 2

7

Robert Arthur

Last week, we found something odd about the way the league started pitching a slumping Oakland. This week, we might have found the reason.

In last week’s column, I shared an observation I’d made about the pitch selection used against the Oakland Athletics. I found that sometime midway through the season, opposing pitchers had subtly but noticeably altered the frequency at which they threw fastballs. Suddenly, the Oakland A’s were being approached with a reduced number of heaters*:

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October 2, 2014 5:33 am

Moonshot: Fastballs and the Collapsing A's

23

Robert Arthur

What does it mean that the league suddenly shifted its pitch selection just as the A's suddenly shifted into a full-scale meltdown?

The Oakland Athletics completed their second-half collapse in true Oakland fashion by failing somehow to advance in the postseason against the Royals. For a season in which Beane went all-in by trading future potential for current performance, in which the A’s began the year an unstoppable, historic juggernaut, the inglorious ending has to smart.

The A’s of this year embodied one of the most beloved playoff myths, that the second half of a team’s performance predicts how that team will do in the playoffs. I say “myth” because, at least in the aggregate, there is little or no evidence in support of this idea, and so it has been debunked on numerous occasions. And yet, there may not be a better example of that phenomenon in action than this team, which roared out to an incredible start to the season, on pace to challenge run-differential records, only to buckle in the second half, barely making the playoffs.

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September 19, 2014 6:00 am

Moonshot: Detecting the Best Medicine

6

Robert Arthur

Can we figure out which teams are best at preventing injuries?

At the team level, injuries are as mysterious as they can be crippling. The Texas Rangers are suffering a whirlwind of pitcher injuries that threatens to break records and has certainly been one of the primary causes of their disappointing season. Meanwhile, teams full of aged veterans like the Yankees and Phillies have somehow managed to evade their fair share, albeit without benefiting very much.

Differences like these suggest asking whether some teams are better at limiting injuries than others. Ben Lindbergh (with the help of Russell Carleton) tried to tackle this issue a few days ago in the context of the Pirates' remarkable run of injury prevention. They found little detectable signal of any team having an ability to reduce injuries.

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The bigger strike zone has caused more than just increased strikeouts.

Recent analysis from Jon Roegele and Brian Mills (among others) has shown that the strike zone is changing. Specifically, the lower edge of the zone has dropped several inches in the last few years, opening up a new area for pitchers to attack. Responding to the deeper zone, pitchers have peppered this region with strikes and sinkers.

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