There are few more enduring — some might even say charming — aspects of baseball than arguments over balls and strikes. They’re expressed in a pitcher’s glare, a batter’s eye-roll, an R-rated chirp from the dugout. And occasionally they result in a manager rushing from the dugout and a loud, dust-kicking, cap-tossing, in-the-face argument with an ump.

That inevitably results in the manager getting tossed, because Major League Baseball has a rule banning them from even approaching the plate to protest a call.

While umpires are usually correct in interpreting baseball’s definition of the strike zone and whether a ball traveling upward of 90 or 100 mph passes over the plate or misses high or low, they’re wrong often enough. And a Washington Post study of umpires’ calls this season shows they are missing strike calls at an increasing rate.

The advent of technology to track pitches and broadcast virtual strike zones to viewers has not only exacerbated the grumbling over calls — because now everyone can see a pitch’s location, often in real time — it also has allowed for the examination of a growing trend: the inconsistency of umpires calling strikes on pitches in the zone.

A study conducted by The Post based on pitch-tracking data from TruMedia and Baseball Prospectus through the games of Aug. 1 showed umpires appear to be squeezing pitchers in 2021. Specifically, pitches that should have been called strikes this season have instead been called balls at a higher rate than ever before.

Side-by-side comparisons of the strike zone of every umpire in the majors also showed significant disparity and subjectivity as to what pitches are called strikes by certain umpires. Additionally, certain teams and pitchers are feeling the effects of this inaccuracy more acutely than others, while on the whole veteran pitchers tend to get more strike calls than their younger peers.

The problem behind the plate

So far this season, umpires are calling fewer strikes than at any point since 2008, the first year sophisticated pitch tracking was available.

MLB’s pitch tracking apparatus, Pitchf/x, debuted during the 2006 playoffs and consists of a camera-based system in every stadium that measures the trajectory, speed, spin, break and location of each pitch. That allows everyone to see where a pitch crosses the plate.

Because the strike zone, at least on paper, is specifically defined in its construction (over home plate from the midpoint between a batter’s shoulders and the top of the uniform pants and a point just below the kneecap), this pitch information can be matched against an individual batter, telling if the pitch should have been called a strike or a ball.

The data then shows not only whether the actual call was correct but also how often a pitcher gets a call on a particular pitch on average. That’s how it can be determined whether a perfectly placed fastball down and away by Washington Nationals starter Patrick Corbin to the Baltimore Orioles’ Trey Mancini, shown below, is a strike 95 percent of the time, despite home plate umpire Chris Conroy calling it ball two.

According to data compiled and classified by TruMedia — a provider of data analytics tools, visualizations and video scouting tools to more than 100 professional sports teams — umpires made 11,644 incorrect calls on balls and strikes in 2020, equaling about 6.5 poor calls per game.

This year there were 19,315 incorrect calls through Aug. 1, averaging out to 6.1 per game. While the rate of incorrect calls has remained steady in recent years, the impact of those calls is the highest it has ever been, largely because of umpires calling fewer strikes than expected since the data became available 13 years ago. Overall, 776 fewer strikes have been called than should have been based on location and who was at bat. By comparison, during the first half of the 2019 campaign there were 79 more strikes called than expected. In 2018 there were 31 fewer strikes called than expected during the first half of the season.

Edwin Moscoso has the least-friendly strike zone to pitchers in 2021. The second-year umpire has called 108 pitches routinely labeled strikes as a ball this season, costing pitchers an estimated 16 earned runs in 24 games worked, the highest in the majors. By contrast, Doug Eddings is the umpire pitchers may want to see behind the plate. He has called 113 strikes that are normally balls, based on pitch location this year, saving pitchers an estimated 18 runs over 21 games behind the plate.

The difference of one strike in an at-bat can be massive. For example, hitters are batting .318 with an .840 on-base-plus-slugging percentage through Aug. 1 when the count is 0-1. That drops to .142 with a .369 OPS when the count is 0-2. It spikes back to .339 with a .918 OPS if the count is instead 1-1. In terms of runs, TruMedia’s model estimates pitchers have allowed 111 more runs than expected in 2021 because of these missed calls.

With this dynamic working against a majority of the pitchers this season, it stands to reason hitters would be having a banner year offensively, but that is far from the case. In fact, hitters started the season having their worst performance in over a century. This may be correcting somewhat after MLB’s crackdown on the application of sticky substances on baseballs by pitchers, but if the major league batting average of non-pitchers (.246) is sustained for the remainder of the season, it would be the third-worst mark in baseball history.

That overall dominance by current major league pitchers obscures the impact of missed calls behind the plate. However, when this issue is examined to look at how it affects teams in the standings and players at the bargaining table, the significance of these missed calls becomes clear.

How it impacts teams

Even though missed strike calls are random from game to game, some teams have felt the impact more than others, both in a given game and across the season. For example, take a look at how inconsistent the strike zone was when the Texas Rangers and Chicago White Sox met April 24. Umpire Chris Segal had different strike zones for each team.

The images below show where in the strike zone a team’s pitchers did or didn’t get a called strike. The White Sox pitchers’ zone is depicted on the left, and the Rangers pitchers’ is on the right. The solid black box represents the strike zone, while the colored areas represent pitch locations during the game. The blue areas indicate fewer strikes called compared to what we would expect based on how that pitch is called throughout the majors, while the red zones indicate more strikes called than expected.

Chicago got calls down and away to right-handed batters, while Texas struggled to get those same called strikes. The White Sox also benefited from calls inside to right-handed batters. The Rangers had less success on those same pitches. And some of the blue area for the Rangers is actually in the strike zone itself. This means pitches that should be called strikes by definition were instead called balls in favor of the hitter.

No team has more of a gripe regarding missed calls on a season-long basis than the Baltimore Orioles. The O’s have seen 147 pitches called balls that should have been strikes, the biggest discrepancy of 2021. Data from TruMedia estimates these missed calls have led Baltimore to allow 21 more runs than expected in 2021. For comparison, the Kansas City Royals are next on the list with an estimated 11 more runs allowed because of missed strike calls this season. The Rangers have received the friendliest strike zone. Their pitchers have benefited from 130 more strike calls on pitches usually considered balls, saving them an estimated 18 runs allowed.

This isn’t the first year the Orioles have been the victims of a poor strike zone. Since 2018 they have seen their strike zone get worse and worse, with this year one of the worst yet for their pitchers. The Rangers, on the other hand, have seen their strike zone improve for their pitchers starting in 2018.

Getting more strike calls than you should in a game is going to net you more wins. Over the past decade, teams that get five pitches that are incorrectly called strikes have an 892-801 record (.527). Teams that got 10 more strike calls than expected in a game are 23-8 (.742). Teams with no extra called strikes largely break even in their matchups.

The impact on players

A lack of strike calls at the team level could manifest itself in two ways. Perhaps a bunch of pitchers spread out over the roster each get a few, thus lessening the impact to any one individual. Or, as in the case of the Orioles, a few pitchers could be carrying much of that burden.

For example, on all pitches thrown in the defined strike zone, Matt Harvey is only getting a strike call on 79 percent of them. That’s the lowest percentage among starters with at least 75 innings pitched. For comparison, Mike Minor of the Royals is next with an 84 percent correct call rate.

Harvey’s teammate Jorge López has the right to be frustrated, too. He has seen 86 percent of pitches called correctly in the strike zone, which helps explain his 12 losses in his first 23 starts this season.

Harvey has been a victim of poor strike zones for a few years now, coinciding with his departure from the New York Mets in 2018. Since then he has seen a below-average rate of called strikes relative to the majors overall, with this year being the worst on record.

Seeing two pitchers over the age of 30 struggle with the called strike zone is unusual. MLB’s data suggests umpires may have a familiarity bias; older pitchers are getting the benefit of the doubt more often than younger pitchers. For example, pitchers between 24 and 26 years old have seen 80 fewer called strikes than expected, which has cost them nearly 12 earned runs this season. Pitchers 35 and 36 years old have benefited from 10 more called strikes than expected, saving them six earned runs in 2021. Since 2008, the increase in balls called strikes for pitchers follows a straight line as they get older.

This carries a financial impact for pitchers, too. Strikeouts are a primary barometer of how well a pitcher performs, and those with higher strikeout rates tend to garner the most money. If they benefit from a pitcher-friendly strike zone during a free agent year, that will translate to higher future earnings.

For example, Trevor Bauer had the highest strikeout rate from 2019 to 2020 (30 percent) among free agent starting pitchers, and he got a $102 million contract over three years. Charlie Morton was not far behind (29 percent) and got a one-year, $15 million deal. Drew Smyly, Corey Kluber and Garrett Richards had above-average strikeout rates, and each signed a deal that paid him at least $10 million per year for 2021. Mike Foltynewicz had a two-year strikeout rate of 21 percent and signed for $2 million, twice what Félix Hernández (18 percent strikeout rate) signed for.

Over the past decade, free agent starting pitchers who received a favorable strike zone over the course of the season ended up earning a contract with a higher average annual value than those who didn’t. On average it was a difference of about $1.3 million per year. Free agent relief pitchers benefiting from a friendlier strike zone over the past 10 years made $700,000 more per year on their free agent deals.

Free agent pitchers from 2011 to 2020
Pitcher-friendly strike zone
Hitter-friendly strike zone
Net difference
Starting pitchers
$ 7,585,757
$ 6,289,548
$ 1,296,208
Relief pitchers
$ 3,013,177
$ 2,310,690
$ 702,487
Source: Spotrac

Umpires are human and will make mistakes. One botched call here or there typically doesn’t amount to much. But it is clear that if a pitcher, or a team, is on the wrong side of numerous incorrect calls it becomes a huge detriment — one that affects not only their wins and losses but players’ career earnings as well.