Al Leiter and Perceived Velocity Illustrated

https://probaseballinsider.com/effective-velocity-what-is-it-how-is-it-used-how-can-it-help-pitchers/

Yes — Al Leiter is essentially correct.

https://www.facebook.com/61578486328634/videos/1329824335715539/

Trackman/Statcast perceived velocity is derived from the pitch’s release velocity (the peak/near-release speed, sometimes informally called “muzzle velocity”) adjusted for the pitcher’s release extension. It is not based on the ball’s speed later in flight or at the plate.

Definitions

• Release velocity (what most people call “velocity” on a gun or in Statcast): Peak speed of the ball, typically measured very near release. This is the actual ball speed leaving the hand.
• Extension: Distance (in feet) from the front of the pitching rubber to the release point. Longer extension = ball released closer to the plate.
• Perceived velocity: Release velocity normalized to the league-average extension so it better reflects the reaction time available to the hitter.

From the MLB.com Statcast glossary: Perceived velocity factors in the velocity of the pitch and the release point. A 95 mph pitch released 7 feet in front of the rubber reaches the hitter faster (and “looks” faster) than the same 95 mph pitch released only 6 feet in front.⁠MLB

The Formula

The common practical approximation used in the industry (including by coaches like Tom House) is:

$$\text{Perceived Velocity} \approx \text{Release Velocity} + 3 \times (\text{Extension} - \text{League Avg Extension})$$

• Extension and league-average extension are in feet.
• The constant 3 mph per foot is the widely cited rule of thumb (“every one foot of distance is three miles per hour to the batter’s eye”).⁠Teammstrd
• League-average extension in recent MLB data is roughly 6.4–6.5 feet.

Example:
A pitcher throws 95 mph with 7.5 feet of extension (league average = 6.5 ft):

$$95 + 3 \times (7.5 - 6.5) = 95 + 3 = 98 \text{ mph perceived velocity}$$

Key Point on Measurement

Statcast/Trackman reports velocity as the peak speed near release. Perceived velocity then takes that number and adjusts it solely for how much closer (or farther) the release point is relative to the average. It does not start from a later measurement of ball speed.

This is why pitchers with long strides and good extension (e.g., Tyler Glasnow historically) can make their fastballs “play up” in perceived velocity even if the raw release speed is unchanged.

Here’s a clear visual breakdown of perceived velocity:              

Courtesy of Grok!

Key idea in the visual: Longer extension moves the release point closer to the plate, so the same release velocity “looks” faster to the hitter because there is less reaction time. The common rule of thumb is roughly +3 mph of perceived velocity per extra foot of extension above the league average (~6.4–6.5 ft).

Here’s a side-by-side comparison of two pitchers illustrating how extension affects perceived velocity:

Courtesy of Grok!

Takeaway: Both pitchers can throw the same 95 mph release velocity, but the pitcher with greater extension releases the ball closer to the plate. That shorter distance reduces the hitter’s reaction time, so the pitch is perceived as several mph harder.

MLB pitcher extension data (Statcast / Baseball Savant, 2025 season, min. 500 pitches)

League average extension is typically ~6.4–6.5 feet. Longer extension moves the release point closer to the plate and increases perceived velocity (roughly +1.7 to +3 mph per extra foot above average, depending on the model).

Top Extension Leaders (2025)

Rank	Pitcher	Throws	Pitches	Extension (ft)
1	Jacob Misiorowski	R	1,164	7.5
2	Tyler Glasnow	R	1,480	7.5
3	Logan Gilbert	R	2,156	7.5
4	Jordan Romano	R	701	7.4
5	Brent Suter	L	1,137	7.4
6	Cade Smith	R	1,182	7.4
7	Carson Palmquist	L	705	7.4
8	Grant Taylor	R	610	7.3
9	Devin Williams	R	1,115	7.3
10	Alek Jacob	R	586	7.3
11	Joey Cantillo	L	1,637	7.3
12	Aroldis Chapman	L	917	7.3
13	Johan Oviedo	R	665	7.3
14	Bailey Ober	R	2,356	7.3
15	Garrett Whitlock	R	1,180	7.3

Data from Baseball Savant Statcast search (2025 regular season).

Quick context

• Pitchers at 7.5 ft are roughly 1 full foot above average. On a 95 mph fastball that can translate to roughly +2–3 mph of perceived velocity.
• Classic long-extension names like Glasnow and Gilbert continue to rank at the top.
• Shorter pitchers who rank high relative to their height (e.g., historically Strider or McClanahan) gain an especially noticeable “plays up” effect.

Tampa Bay Rays pitcher extension data (Statcast, primarily 2025–2026)

League average extension is roughly 6.4–6.5 feet. Longer extension shortens the effective distance to the plate and increases perceived velocity.

Key Rays Pitchers

Pitcher	Role	Approx. Extension	Notes
Shane McClanahan	LHP	~6.6–6.7 ft	Solid extension (roughly 68th percentile in 2026 samples). Historically strong relative to height; limited by injury in 2026.
Drew Rasmussen	RHP	~6.6–6.7 ft	Above-average extension (around 69th percentile in available samples). Efficient delivery helps his stuff play up.
Freddy Peralta	RHP	~6.5–6.7 ft	Slight improvement after joining the Rays (reported from ~6.5 ft earlier in 2026 to ~6.7 ft). Extension is a notable part of his profile.