Prep Baseball Report

Underclass Top Prospect Games: Pitching Data Dive


Cam Black-Araujo
Arizona Operations

This past Monday and Tuesday, the Prep Baseball Arizona staff continued it's Summer Tour as we hosted our marquee event of the summer for underclassman with the Underclass Top Prospect Games at American Family Fields of Phoenix, the Spring Training home of the Milwaukee Brewers. This event featured roughly 25 prospects from the 2027 and 2028 classes and featured several top players within their respective classes.

The event allowed our staff to collect updated data on all athletes following their high school season, as well as see how they perform and handle themselves within game action competing against other high-evel players.

Earlier this week, we broke down the top measurable data performers from the event with our Statistical Analysis article. Now, we will take a further in-depth look at the top pitchers with the help of our tech partnerships, broken down by the categories down below:

For complete event results, click here.
To view upcoming event schedule, click here.

FASTBALL

MAX VELOCITY (MPH)

Rank Name State School Class Pos Velocity (max)
1 Maverick Bolen AZ Horizon High School 2027 C 83.6 mph
2 Evan Rios AZ N/A 2028 RHP 80.7 mph
3 Hunter Halvorson AZ Chaparral High School 2027 RHP 79.3 mph
4 Peyton Burgess AZ Millennium High School 2028 C 79.2 mph
5 Kohler Mobley AZ Shadow Ridge High School 2028 C 78.4 mph

Max Fastball Velocity: This metric calculates the speed of the pitch as it’s released from the pitcher’s hand.

SPIN RATE (AVG)

Rank Name State School Class Pos Spin Rate (avg)
1 Maverick Bolen AZ Horizon High School 2027 C 2186 rpm
2 Peyton Burgess AZ Millennium High School 2028 C 2045 rpm
3 Xzaiver Trujillo AZ Tolleson Union High School 2027 OF 1976 rpm
4 Hunter Halvorson AZ Chaparral High School 2027 RHP 1955 rpm
5 Kohler Mobley AZ Shadow Ridge High School 2028 C 1843 rpm

Spin Rate: This metric calculates the rate of spin on the baseball as it leaves the pitcher’s hand, measured in revolutions per minute (rpm). Historical data shows that high-spin fastballs lessen the impact of gravity, allowing for more ‘rise’ (or less fall, in other words) as it carries through the zone. Low-spin fastballs typically indicate the pitch has greater horizontal action, often making it tougher to square up, but generally easier to make contact with, leading to more ground balls, while high-spin fastballs show a correlation with swings and misses.

INDUCED VERTICAL BREAK (AVG.)

Rank Name State School Class Pos IVB (avg)
1 Evan Rios AZ N/A 2028 RHP 17.1 in
2 Jack Josephson AZ Chaparral 2027 SS 16.1 in
3 Hunter Halvorson AZ Chaparral High School 2027 RHP 15.8 in
4 Peyton Burgess AZ Millennium High School 2028 C 13.7 in
5 Kohler Mobley AZ Shadow Ridge High School 2028 C 13.1 in

Induced Vertical Break: Used in short form as "IVB," this metric is most important on fastballs for creating rise and on curveballs for creating depth – it can also have some use when measuring sliders and cutters as well. Sliders tend to be closer to zero inches while cutters are generally between 5 and 15 inches. Usually fastballs and curveballs with large IVB have higher spin efficiencies as well. Sliders generally have very little (closer to zero) IVB and very low spin efficiency. You could also categorize IVB into spin rate as this is part of the “useful movement” you’re looking for. IVB is also a huge part of the vertical approach angle.

HORIZONTAL MOVEMENT (AVG.)

Rank Name State School Class Pos HM (avg)
1 Kohler Mobley AZ Shadow Ridge High School 2028 C 10.8
2 Xzaiver Trujillo AZ Tolleson Union High School 2027 OF 10.2
3 Evan Rios AZ N/A 2028 RHP 9.3
4 Peyton Burgess AZ Millennium High School 2028 C 9.2
5 Maverick Bolen AZ Horizon High School 2027 C 9.2

Horizontal Break: Outlined on TrackMan’s own website: “... horizontal movement is measured in inches between where the pitch actually crosses the front of home plate side-wise, and where it would have crossed home plate side-wise if had it traveled in a perfectly straight line from release. A positive number means the break was to the right from the pitcher’s perspective, while a negative number means the break was to the left from the pitcher’s perspective.”

STRIKE ZONE RATE%

Rank Name State School Class Pos Zone %
1 Evan Rios AZ N/A 2028 RHP 60 %
2 Xzaiver Trujillo AZ Tolleson Union High School 2027 OF 59 %

CURVEBALL

SPIN RATE (AVG.)

Rank Name State School Class Pos Spin Rate (avg)
1 Maverick Bolen AZ Horizon High School 2027 C 1927 rpm
2 Jack Josephson AZ Chaparral 2027 SS 1586 rpm

INDUCED VERTICAL BREAK (AVG.)

Rank Name State School Class Pos IVB (avg)
1 Evan Rios AZ N/A 2028 RHP 17.1 in
2 Jack Josephson AZ Chaparral 2027 SS 16.1 in
3 Hunter Halvorson AZ Chaparral High School 2027 RHP 15.8 in
4 Peyton Burgess AZ Millennium High School 2028 C 13.7 in
5 Kohler Mobley AZ Shadow Ridge High School 2028 C 13.1 in

HORIZONTAL MOVEMENT (AVG.)

Rank Name State School Class Pos HM (avg)
1 Jack Josephson AZ Chaparral 2027 SS -9.2
2 Maverick Bolen AZ Horizon High School 2027 C -0.4

SLIDER

SPIN RATE (AVG.)

Rank Name State School Class Pos Spin Rate (avg)
1 Xzaiver Trujillo AZ Tolleson Union High School 2027 OF 1991
2 Hunter Halvorson AZ Chaparral High School 2027 RHP 1912
3 Kohler Mobley AZ Shadow Ridge High School 2028 C 1784
4 Peyton Burgess AZ Millennium High School 2028 C 1757
5 Evan Rios AZ N/A 2028 RHP 1675

INDUCED VERTICAL BREAK (AVG.)

Rank Name State School Class Pos IVB (avg)
1 Evan Rios AZ N/A 2028 RHP -3.7 in
2 Hunter Halvorson AZ Chaparral High School 2027 RHP -3.1 in
3 Kohler Mobley AZ Shadow Ridge High School 2028 C 2.7 in
4 Xzaiver Trujillo AZ Tolleson Union High School 2027 OF 2.2 in
5 Peyton Burgess AZ Millennium High School 2028 C -1.9 in

HORIZONTAL MOVEMENT (AVG.)

Rank Name State School Class Pos HM (avg)
1 Xzaiver Trujillo AZ Tolleson Union High School 2027 OF -9.1
2 Hunter Halvorson AZ Chaparral High School 2027 RHP -8.3
3 Peyton Burgess AZ Millennium High School 2028 C -6.4
4 Evan Rios AZ N/A 2028 RHP -4.4
5 Kohler Mobley AZ Shadow Ridge High School 2028 C -2.2

CHANGEUP

HORIZONTAL MOVEMENT (AVG.)

Rank Name State School Class Pos HM (avg)
1 Maverick Bolen AZ Horizon High School 2027 C 17.1
2 Kohler Mobley AZ Shadow Ridge High School 2028 C 15.8
3 Peyton Burgess AZ Millennium High School 2028 C 9.1
4 Jack Josephson AZ Chaparral 2027 SS -2.6

UPCOMING EVENTS

SHOWCASE STATE DATE LOCATION
West Side Summer ID AZ 06/18 Canyon View High School - Waddell, AZ
Glendale Summer ID AZ 07/16 Apollo High School - Glendale, AZ
Future Games (Class of 2026/27) NATIONAL 07/24 LakePoint Sports
Junior Future Games (Class of 2028/29) NATIONAL 07/24 LakePoint Sports
Senior Future Games (Class of 2025) NATIONAL 07/24 LakePoint Sports

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