Prep Baseball Report
No Player Image

CLASS OF 2019

RHP

William
Kempner

Gonzaga
Valley Christian (HS) • CA
6' 0" • 225LBS
R/R • 22yr 9mo
Travel Team: Zoots

Rankings

2019 National

Rankings available to Premium Subscriber

Log In Subscribe to PBR Plus

2019 State

Rankings available to Premium Subscriber

Log In Subscribe to PBR Plus

Commitment

2022 DRAFT Giants ROUND 3 PICK
Is this your profile? learn how you can edit it.

Videos

This Area is only available to PBR Premium Content Subscribers.

Best of Snapshot
Pitching Velos
News
Comments
Contact

Best Of Stats

Pitching

Fastball

-
Velocity (max)
85 - 88
Velo Range
3/23/19
-
Spin Rate (avg)

Slider

71 - 73
Velo Range
2/16/19
-
Spin Rate (avg)

Positional Tools

Hitting

Hitting

Pitching

Pitch Scores

Pitching Velos

2019
Fastball
Velocity Max
90.0
Fastball
Velocity Avg
86.0
Slider
Velocity Avg
71.5
3/23/19 v Jesuit
Mar 23, 2019
Pitching
89
Max FB
85 - 88
FB
70 - 72
SL
Game vs De La Salle
Feb 16, 2019
Pitching
90
Max FB
85 - 86
FB
71 - 73
SL

Game Performance

Visual Edge

Pitch Ai

Notes

Comments

5/22/22

The 6-foot, 220-pounder missed nearly two months with a finger injury, but returned on May 1 and hasn't allowed a run since. On Saturday, he went five innings, allowing just one hit and two walks while striking out eight. He's up tempo on the mound with a big drop step in his windup before coming at hitters from a sidearm slot. His fastball is straight cheddar, but not straight at all, showing serious sink and run. He was up to 98 in the first, pitching mostly at 94-96 for the outing with spin rates above 2600 rpm. It gave hitters fits, as he could induce weak contact or get swings and misses, especially against righties as he could really tie them up inside. The slider showed improvement from previous outings, flashing average. It spun at 2700-2800 rpm in the low 80s with hard 10/4 sweep.

3/06/22

Listed at 6-foot, 225-pounds, the right-hander is just more proof that dense mass equals gas. However, this righty is also a unicorn, similar to the Milwaukee Brewers left-hander Josh Hader. Kempner is a sidearmer with a lightning bolt for an arm. It's heavy heat that touches 100 with dart and dive. But it's also one that has caused control issues in the past. During his Saturday start at Oklahoma State, Kempner sat 96-98 during the first couple innings and was still touching 97 in the 6th. His heater is also a high spinner (2630-2720 rpm) adding to the challenge for hitters to square it up.

https://twitter.com/DSeifertD1PBR/status/1500188265143578626

His best off speed offering was a lower spinning (1900s) firm changeup that ranged from 86-89. It played average to better as Kempner tallied three of his five strikeouts via this pitch. The sidewinder's third pitch was a below average slider throw in the low-80s. It wasn't much of a threat as he did not throw any for a strike, whether swinging or looking. It did not grade to be a present usable pitch for the pro level. Kempner will lose some draft value since there are many clubs that won't consider a pitcher who doesn't have at least an average present breaking ball. And although his control was average against Oklahoma State (three walks, five strikeouts), his history paints a different picture with 48 walks, 48 strikeouts in 64 IP during his three-year career, and ten walks, 12 strikeouts in 16 IP so far this spring. Kempner may also benefit by showing his fastball up around the letters a little more often to move the hitter's eyes, rather than pounding away at the knees with nearly every fastball. Although the home plate umpire did a great job after the first two innings adjusting to the velocity and life on Kempner's heat, he may also benefit with pro umpires who likely have more experience with lively upper-90s heaters, as well as catchers who receive it more often. His deception is also not ideal, as the hitters get a pretty good look at the ball before it's released with a long arm swing in back. With all that stated, after the Top 50 overall picks it's all about accumulating assets and Kempner's status as an outlier (sidewinder who touches 100 and a very flat plane/approach angle) is a definite different look talent. With continued solid control as to what he showed in Stillwater expect teams to consider him starting around the third round.

3/23/19

V Jesuit - Gonzaga Commit. Large, thick frame with extra weight in core; length in limbs and chance for body to firm up at the next level. I’ve seen a few outings from Kempner this season and this one was the best one as he went 5IP giving up 2 early hits and striking out 4. Hands start at chin going down to waist and back up to chin with high leg lift and tuck. Drives from balance with good extension down the hill creating small crossfire with front leg. Arm is whippy from M3/4 release point showing length behind the back; when best shows angle down hill with upper half getting over front leg. Times where he gets over-rotational causing arm to get around the ball and pull it out of the zone. FB was 85-88 T89 with arm side run and angle to the glove side; ability to go up the ladder for swing and miss. Control of pitch was much better; got into a rhythm from 2-5th innings where he attacked with FB to both sides of the plate. SLD 70-72 MPH flashed depth with 3/4 bite at it’s best; able to use to both sides of plate and front door on RHH. Pitch had times where it loosened showing cross-plate sweep with flat actions. Control was much better during outing; walked two batters to start 6th inning which ended his day.

2/21/19

It was a rough weekend for the Gonzaga commit taking two L’s and getting rocked by Carroll, unable to get out of the 1st inning. He threw better on Saturday against Orange Lutheran coming in relief and working 2.1 innings showing better angle and control of the fastball. He’s a guy that will need to command the fastball to the inner/outer thirds of the plate to help set up his offspeed pitches. When that FB has angle and run to the armside it makes hitters wary of getting to the outer half and makes the Slider much more effective

2/16/19

vs De La Salle - Gonzaga commit and #65 in the 2019 class, came in for one inning striking out one and walking one. The righty has a large frame with width in the shoulders and some extra young weight still on the frame. It’s a body that can continue to tighten showing a loose arm that has length in the swing with a mid-¾ release and showing some depth behind the back on the swing. His FB was 85-86 T90 MPH once and working mainly to the glove side. There were times where his hand would get around the ball making it cut out of the zone with the angle from his arm. His SLD was 71-73 MPH showing sweepy action with flashes of depth when looking for the punchout. Kempner also threw the SLD 1st pitch to the front side of a righty giving something for hitters to think about. After all the innings lost for the Warriors from 2018, Kempner should be one of the pitchers in 2019 to pick up a big chunk.

7/13/18

USA PDP - Gonzaga commit. Full body type with softer upper body, thick proportions, loose easy arm action, shoulder works quite well, good direction down the slope and maintains good body control throughout. Fastball came out easy though at times got rotational trying to get to higher velocities. Sink can be above average and life on all pitches was good. Works quickly and is aggressive. Breaking ball is a slurve-type in the low 70s. Three batter outing (1B FB, F7 FB, K FB away). Stuff is good, arm is good, body will have to likely firm up to not only maximize his talent but also to gain interest from the pro side. There is plenty to like in the arm talent.

Draft Reports

Contact

Premium Content Area

To unlock contact information, you need to purchase a ScoutPLUS subscription.

Purchase Subscription
OR
Login

Twitter

Physical