What's Behind Baseball's Hit-by-Pitch Epidemic?

Dodgers shortstop Corey Seager became the latest MLB star this season to land on the injured list because of MLB's surge in hit-by-pitches.

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An epidemic put Corey Seager and Joey Votto on the injured list. It caused Bryce Harper, Mike Trout, Mookie Betts, Ronald Acuña Jr. and Shohei Ohtani to leave games or miss time. It has made baseball today more dangerous for hitters than any other time in the past 120 years. The epidemic is the hit-by-pitch, and there is no sign of it slowing.

Another 45 batters were hit in the 46 games played over the weekend, including Seager. The Dodgers shortstop, playing in his platform season to free agency, suffered a broken hand and is out for at least four weeks. What is scary is that there was nothing unusual about this past weekend.

Batters are getting hit at a rate of almost one every game. The four most dangerous seasons for hit by pitches since the AL joined the NL in 1901 are this year (0.92 batters per game), last year (0.92), the year before that (0.84) and the year before that (0.80).

What in the name of Ron Hunt is going on?

Philadelphia Phillies shortstop Didi Gregorius (18) falls to the ground after he was hit by a pitch from St. Louis Cardinals relief pitcher Génesis Cabrera. Right fielder Bryce Harper was hit in the face by Cabrera's previous pitch, making it two HBPs on two pitches to begin the sixth inning on April 28 :: Jeff Curry/USA Today Sports

1. Pitchers value velocity over command.

Let me get this one out of the way. This is the knee-jerk reaction to most every trend in pitching, but it’s simply not as impactful as you are told by off-the-cuff commentary.

Yes, pitchers are throwing harder. Average fastball velocity is 93.3 mph, up from 92.8 mph just three years ago. But fastball use is down sharply—from 54.5% three years ago to 50.5% this year.

And fastballs are increasingly less to blame for hit by pitches. Three years ago, they accounted for 54.5% of pitches and 57.3% of hit batters. This year they account for 50.5% of pitches and 49.4% of hit batters. Batters are less likely to get hit by fastballs.

2. Armor

This is the biggest reason why hit by pitch rates are growing. More and more batters are wearing protective guards on their lead elbows and upper arms—sometimes both. The guards create a confidence that encourages hitters not to attempt to get out of the way of inside pitches.

Check out what almost all the hit by pitch leaders this season have in common:

Most HBP, MLB 2021

	HBP	Elbow Guard?
Mark Canha, Athletics	9	Yes
Nick Solak, Rangers	7	Yes
Willson Conteras, Cubs	6	Yes
Jackie Bradley Jr., Brewers	6	Yes
Marwin Gonzalez, Twins	6	Yes
Jonathan India, Reds	6	Yes
Sean Murphy, Athletics	6	No

The elbow guard is creating a similar unintended cycle as what happened with helmets in the NFL. The more helmets were made safer, the more they emboldened players to use their heads more aggressively in blocking and tackling. Rules had to be written to discourage such use. Hitters are using arm and elbow guards as a response to more hit by pitches, but the guards are creating even more hit by pitches because those who wear them have changed how they react to inside pitches, which is not to move or even to intentionally put the guarded elbow in the path of the pitch.

From 2010 to '11, no hitter was hit by a pitch that was in the strike zone. This season, it has happened twice already: by Michael Conforto and Trout. Both were hit on the elbow pad.

3. Fastballs are more dangerous.

Pitching has morphed from an east-west orientation to a north-south one, as the high four-seam fastball has become the antidote to the launch angle generation.

The average height of fastballs is getting higher, and thus you see more pitches up and in to hitters. Those are pitches everybody notices, especially hitters who don’t take kindly to having their hands and heads threatened.

There is a big difference—and a growing one—between the height of a fastball that hits a batter (3.51 feet off the ground this year, which is at a hitter's upper arm, near the shoulder) and the height of all other pitches that hit batters.

HBP Average Height, MLB

Year	Fastballs	Non-Fastballs	Difference
2018	3.46	2.14	1.32
2021	3.51	1.86	1.65

4. The most dangerous pitch is the arm-side fastball to same-side hitter.

An arm-side pitch is a pitch to the same side of the plate as is the pitcher’s throwing arm. The most dangerous pitch is a fastball thrown by a right-handed pitcher to a right-handed hitter or one thrown by a left-handed pitcher to a left-handed hitter. That’s the one that broke Seager’s hand. The breakdown by pitch type and side of the plate:

MLB Hit by Pitches, 2021

	HBPs
Arm-Side Fastballs	201
Glove-Side Non-Fastballs	185
Arm-Side Non-Fastballs	95
Glove-Side Fastballs	72

In general, pitchers hit same-side batters (i.e., right vs. right) when they lose fastballs up and in; they can’t command fastballs designed to be effective inside pitches above the hands of the hitter. They mostly hit opposite-side batters (i.e., right vs. left) when they pull breaking pitches and cutters designed to be under the hands of the hitter.

5. Velocity and spin rate is the fast track to the big leagues, not command.

Teams have used 595 pitchers to cover the first six weeks of the season. That’s more than were needed to cover the entire 2001 season (591).

The specialty nature of bullpen use (and frequent turnover) has created this gig economy of relievers. The highest hit by pitch rates this year among pitchers with 200 or more pitches belong to specialty relievers Austin Adams of the Padres (2.9% of pitches), who throws 89% sliders; Austin Brice of the Red Sox (1.7%), a sidearmer; and Nabil Crismatt of the Pirates (1.7%), a rookie changeup specialist.

It’s not just hit by pitches. Wild pitches are up 28% in the past 10 years. The seven highest rates of wild pitches since 1900 have all occurred in the past seven years, including a high of 0.82 wild pitches per game this year. The walk rates the past two seasons (9.2% and 9.0%) are the highest in 20 years. In 10 years, the combined per-game rate of hit batters, wild pitches and walks has increased 13%.

Hitting has never been so dangerous. What can be done about this epidemic? One MLB executive floated the idea of giving the hit batter two bases, not just one, to encourage pitchers to get the ball over the plate. Pitches that hit elbow and arm guards could be ruled a ball, with no base awarded. Neither is likely to happen. What is more likely is that more players will continue to be hit by pitches at a record rate, which means more stars like Seager will lose playing time by getting hit on high, same-side fastballs.