The Dawn of Velocity Measurement
The first official pitch speed measurements in Japanese professional baseball date to the late 1970s. Radar guns developed in the United States were brought to Japan, and TV broadcasts began displaying pitch speeds around 1977. The dominant equipment at the time was manufactured by JUGS, with measurement accuracy estimated at roughly ±3 km/h. Before this era, the velocities attributed to pitchers like Tsuneo Horiuchi and Masaichi Kaneda were merely estimates derived from frame-by-frame film analysis, and Kaneda's legendary claim of exceeding 160 km/h lacked scientific verification. The introduction of speed guns was a groundbreaking development that brought a culture of evaluating pitchers by objective numbers to NPB. By the 1980s, velocity displays became a permanent fixture on stadium scoreboards, making pitch speed an integral part of the fan experience.
Generational Shifts in Measurement Technology
The 2000s saw the emergence of more sophisticated measurement systems beyond traditional Doppler radar guns. Trackman, introduced to multiple NPB stadiums around 2014, uses 3D Doppler radar to simultaneously capture not only velocity but also spin rate, spin axis, and movement. In the 2020s, the Hawk-Eye system arrived, employing 12 high-speed cameras for optical tracking of the ball's entire trajectory. This enables recording of release point height and pitch location with millimeter-level precision. Differences in measurement methods also affect the numbers. Traditional speed guns tended to measure initial velocity just after release, while Trackman calculates average speed from release point to home plate, which can produce differences of 2 to 3 km/h for the same pitch.
| Method | Adoption in NPB | Main data captured | Precision and characteristics |
|---|---|---|---|
| Speed gun (Doppler radar) | Velocity shown on TV broadcasts from around 1977 | Velocity | Early units were said to carry an error of about 3 km/h |
| Trackman (3D Doppler radar) | Multiple stadiums from around 2014 | Velocity, spin rate, spin axis, movement | Calculates average speed from release point to home plate |
| Hawk-Eye (optical, 12 high-speed cameras) | 2020s | Full pitch trajectory, release point height, pitch location | Records with millimeter-level precision |
Because some methods read the velocity just after release while others average the flight, the same pitch can differ by 2 to 3 km/h.
Speed Records and Impact on Pitcher Evaluation
The fastest pitch ever displayed in an NPB official game is 166 km/h, thrown by Thyago Vieira (Yomiuri) in August 2021. The fastest by a Japanese pitcher is 165 km/h, by Shohei Ohtani (2016 Climax Series, then with Nippon-Ham) and Roki Sasaki (2023, Lotte); all of these are reference figures based on stadium readings rather than records officially certified by NPB. Earlier, Marc Kroon's 162 km/h (Yokohama, 2008) and, before that, Hideki Irabu's 158 km/h (Lotte, 1993) had long stood as the fastest marks. As measurement technology has advanced, pitchers exceeding 150 km/h have become commonplace; in the 2023 season, over 60 NPB pitchers recorded velocities above that threshold. However, the tendency to judge pitchers solely by velocity has drawn criticism. Many pitchers have dominated through non-velocity attributes, such as Shigeru Sugishita's forkball or Hideo Nomo's tornado delivery. Today, qualitative metrics like spin rate and movement are increasingly valued, and the understanding that velocity is just one component of pitcher evaluation is gaining ground.
| Year | Pitcher (team at the time) | Displayed velocity |
|---|---|---|
| 1993 | Hideki Irabu (Lotte) | 158 km/h |
| 2008 | Marc Kroon (Yokohama) | 162 km/h |
| 2016 | Shohei Ohtani (Nippon-Ham) | 165 km/h |
| 2021 | Thyago Vieira (Yomiuri) | 166 km/h |
| 2023 | Roki Sasaki (Lotte) | 165 km/h |
Ohtani's 165 km/h came in the Climax Series. All of these are reference figures based on stadium readings, not records officially certified by NPB.
Future Outlook
Velocity measurement technology is poised for further evolution. In MLB, all 30 stadiums have been equipped with Hawk-Eye as standard since 2023, operating the Statcast system that publishes pitch data in real time. NPB is considering similar data-sharing infrastructure, which would significantly change the fan experience and media coverage. Wearable sensors measuring arm angular velocity and shoulder joint load during pitching are also entering practical use, with promising applications in injury prevention. What began as a single number representing pitch speed is evolving into a platform that visualizes the complete picture of a pitch. This transformation will influence scouting, player development, and in-game strategy alike.
Measurement Variations Across Ballparks
The placement and angle of speed guns differ from stadium to stadium, meaning the same pitcher can register different velocities depending on the venue. Systems measuring near the release point and those measuring near home plate can produce readings several kilometers per hour apart, limiting the usefulness of raw speed comparisons. In NPB, each ballpark independently selects its equipment, and no unified standard exists. Broadcast networks also use their own devices, so televised readings sometimes differ from in-stadium displays during the same game. Fans evaluating velocity should keep these measurement conditions in mind.
Physical Toll and the Pitfalls of Velocity Obsession
As velocity became increasingly quantifiable, pitchers began chasing higher speeds, and concerns grew over the rising risk of elbow and shoulder injuries. The growing number of pitchers undergoing Tommy John surgery is often linked to aggressive mechanical adjustments and excessive training loads. At the same time, biomechanics research aimed at increasing velocity while preventing injuries has advanced, with many teams adopting three-dimensional motion analysis to identify high-stress movement patterns. A comprehensive approach that protects long-term pitcher health rather than pursuing speed alone has become a focus across professional baseball.
Ripple Effects on Amateur Baseball
The emphasis on velocity in professional baseball has extended to high school and college levels as well. At the Koshien tournament, displayed speeds attract significant attention, and velocity has become a key metric in evaluating draft prospects. As a result, cases of young pitchers placing excessive stress on developing bodies in pursuit of higher velocity have raised concerns. The Japan High School Baseball Federation introduced pitch-count limits to protect shoulders and elbows. The benefits and drawbacks of velocity as an easily understood metric are now debated not only at the professional level but across all levels of Japanese amateur baseball.
Frequently Asked Questions
Q. What is the difference between initial speed and terminal speed?
Initial speed is the velocity just after release, terminal speed the velocity as the ball reaches the vicinity of home plate; air resistance makes the terminal figure several km/h slower than the initial one. The closer to the plate a device measures, the slower its readings tend to look.
Q. When did pitch speed displays start in Japan?
Radar guns made in the United States were brought over in the late 1970s, and televised broadcasts began showing pitch speeds around 1977. The equipment of that era is said to have carried an error of roughly plus or minus 3 km/h.
Q. What is the fastest pitch in NPB?
The fastest figure displayed in an official game is the 166 km/h thrown by Thyago Vieira (Yomiuri) in 2021 (as of the mid-2020s). The fastest by a Japanese pitcher is 165 km/h, shared by Shohei Ohtani (2016 Climax Series) and Roki Sasaki (2023). All of these rest on stadium displays and are reference figures, not records officially certified by NPB.