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Oakland A's 2016 top-50 prospect scouting report: Corey Walter

Our Oakland A's 2016 top-50 prospects list is out. Now find out more about the players on that list. In this piece, a close look at top-50 prospect Corey Walter. Walter took a big leap forward in 2015, excelling in High-A after skipping Low-A. What's in-store for him in 2016?

Name: Corey Walter 
Position: RHP
Height/Weight: 6’3’’, 215
Bats/Throws: R/R
Age: 23
How Acquired: Selected in the 28th round of the 2014 MLB Draft

It’s rare when a player out-performs his college numbers in the pros, but, thus far, Corey Walter is proving to be one of those exceptions. The right-hander had an underwhelming career at West Virginia, but after a mechanical tweak at the start of his professional career, he has been lights out as a pro.

Walter played four years at West Virginia and finished his NCAA career with a 4.45 ERA and a 128:100 K:BB in 267 innings. The A’s saw some potential in his arm strength and took a chance on Walter in the 28th round in 2014. He has paid back that faith in spades in his two pro seasons thus far.

After signing with Oakland in 2014, Walter spent some time at the A’s complex at the draft mini-camp. During that stint in Arizona, he worked with then-A’s rehab coordinator Garvin Alston on a tweak to his mechanics, changing how he moved his hip through his motion. That one change gave him more energy towards the plate and additional movement on his pitches. He took that adjustment and ran with it through his pro debut season, posting a 2.33 ERA and a 27:11 K:BB in 27 innings between the A’s two short-season squads.

The following spring Walter reported to Arizona still throwing with the improved velocity and pitch movement. He had a strong spring and Alston – who had move into the minor league pitching coordinator position at that point – recommended that the 22-year-old jump straight to High-A. It was a challenge promotion, but the A’s wanted to see how his improved sinker and slider combination would play against more advanced competition.

Corey Walter Stats

2015 STO 57 1.42 40 15 46 1.73 0.96
Career 84 1.71 58 26 73 2.04 1.00

At first, it looked like the Cal League would eat Walter alive. He allowed 11 hits and two walks through his first seven innings. He didn’t get frustrated, however, and soon adjusted to the league. From then on, Walter allowed only 29 hits and 13 walks in 50 innings of work. Even with the slow start, he finished his Cal League season with a sparkling 1.42 ERA and a 46:15 K:BB. Cal League hitters managed only a .197 average against him and he allowed only one homerun.

When Brendan McCurry earned a promotion to Double-A Midland at the start of August, Walter moved into a late-inning role for Stockton. He converted five of six saves. Walter also added four brilliant shutout innings in the Ports’ post-season run, including three with the game tied in a winner-takes-all game versus San Jose. 

Walter has a simple approach: challenge hitters with his 90-94 sinker and his slider. Thus far, he has had the upper-hand. Lefties (.258 BAA last season) have had a bit more success than righties (.145 BAA in 2015), but neither side of the plate has produced much solid contact off Walter. He is an extreme groundball pitcher. More than 61% of all balls hit into play against Walter were hit on the ground last season, and less than 20% were flyballs to the outfield or pop-ups. He induced eight groundball double-plays and half of the line-drives he allowed were in the “right-to-the-fielder” line-out category.

“To go from where he did right to the Cal League is impressive. He really impressed us during the Instructional League,” A’s Director of Player Development Keith Lieppman said. “He has a really heavy, hard sinker and he has developed a little bit better slider. He has shown he can step right in and compete. He has made tremendous advancements this season. He started off a little slow, but we expected it wouldn’t be easy – better competition and a double-jump in levels. He’s handled all of that and he’s very confident right now.”

Walter has a big frame at 6’3’’, 215 and some deception to his delivery that makes his fastball appear even harder than the 90-94 it ranges. Although he was a senior sign, Walter is right in-line with the normal age for his level since his skipped Low-A. The A’s have a number of talented relievers in the upper-levels of their system, but he should get an opportunity to start the year in Double-A with a good spring.

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