The Unconventional Angle: The Rare Commodity, Craft of Baseball’s Sidearm Pitchers
SCOTTSDALE, Ariz. — Ryan Thompson’s untraditional road to the majors arguably started with playing backyard wiffle ball with his friends.
“We were obsessed with baseball,” said Thompson, now a reliever for the Arizona Diamondbacks. “We used to have every roster of every major league team written in a notepad, and we watched so much baseball and played so many video games that we knew all their mechanics. So, when we played in my backyard, we would have to imitate everybody.”
The pitcher he used to imitate most, he said, was Byung-Hyun Kim.
Kim was a submarine pitcher who played for nine years in the majors, mostly with Arizona. Thompson said he perfected Kim’s throwing motion — and realized his friends weren’t able to hit off him.
However, Thompson didn’t actually start using the sidearm motion in games until he was in high school. He said while at a baseball camp after his 10th-grade year, a camp coach told him he looked like he would be more natural throwing sidearm and asked if he had ever tried it.
Thompson’s response: “Oh, have I?”
There have been thousands of pitchers in the history of MLB, but only a select few are part of the exclusive club of sidearmers, who release the ball parallel to their waist. There’s even less submariners, who release the ball from an even more extreme — almost underhanded — position near the ground. While it’s tough to perfect the craft of pitching enough to make it to the highest level in the world, it’s even tougher to do so while throwing from an unnatural angle.
However, the elite ones who have cemented themselves into sidearm royalty present a unique challenge to every batter they face. Hall of Famer Walter Johnson, Dan Quisenberry, Gene Garber and Kent Tekulve paved the way for the current generation of pitchers who dip down below, including Thompson, San Francisco’s Tyler Rogers, Texas’ Hoby Milner and San Diego’s Tim Hill.
For Thompson, a delivery first used to play wiffle ball became his calling card – and the results followed. After high school, Thompson attended Campbell University in North Carolina. In his two years in college, he compiled a 16-3 record with a 1.13 ERA, leading to him being drafted by the Houston Astros in the 23rd round of the 2014 MLB Draft – beginning the journey to his eventual major-league career.
Thompson made his MLB debut in 2020 with the Tampa Bay Rays and has been in the majors ever since. He is one of the premier sidearm pitchers in all of baseball, boasting a sub-4.00 ERA in more than 200 appearances in the big leagues, and is now a big piece in Arizona’s bullpen.
“I think sidearmers are so special because hitters don’t see what we offer very often,” Thompson said. “The less that hitters can see you or see your pitch types, the more of the advantage it is to the pitcher.”
While he started the craft so early in life and had time to improve and perfect it over time, Thompson said it’s hard to find coaches who can help him mechanically, even in the big leagues. The 6-foot-6 sidearmer’s release point provides a challenge.
Thompson’s — and most sidearmers’ — releases can be an advantage over batters but there’s little help with mechanics. Very few people in the world who throw exactly like he does successfully, which makes it difficult for teammates and coaches to give advice.
Because of this, Thompson said he has looked to other sidearm pitchers of the past who have excelled at the big-league level. One former sidearmer he studied was former Gators star Darren O’Day, because O’Day’s delivery was very similar to his own.
“Darren O’Day; he’s an anomaly,” Thompson said. “He’s done it longer than maybe anybody as a sidearm guy and been very good pretty much his entire career. He’s throwing 84 to 86 [mph] up in the zone. It’s always fascinating watching him dominate doing that. He’s out of the game now, and he’s still a trailblazer.”
O’Day spent 15 years in the major leagues, most notably with the Baltimore Orioles, and had a lifetime ERA of 2.59 in more than 600 innings pitched. His incredible baseball career began at the University of Florida, where he spent four years from 2003-06, including a trip to the College World Series in 2005. In his time with the Gators, O’Day racked up 117 appearances with a 23-9 record and a 3.16 ERA.
Thompson, though, is not the only sidearm pitcher Arizona has in its organization. The Diamondbacks have left-hander Kyle Backhus, who is currently at the Triple-A level with the Reno Aces.
“He’s an incredible talent,” Thompson said. “He’s got some stuff that I wish I could do. Me and him don’t perfectly overlap, but he throws hard, he’s got a really good slider. He’s gonna be good for a long time.”
Backhus has been steady in his minor-league career to date. He was signed as an undrafted free agent by Arizona in 2021 after five years at Sam Houston State. Since then, he’s steadily made his way up Arizona’s system and spent the entirety of 2024 in Reno. Through 10 appearances with the Aces this year, he has a 1.46 ERA, striking out 18 while only walking two.
His transition to the lower arm slot came well after he started pitching, but he changed angles at the collegiate level, even later than Thompson.
“It just kinda came natural,” Backhus said. “I used to be over the top, but the lower I got, the funkier it got. In college, I went from starter to reliever, so I had to find something that was a little bit different and throw a little harder. I got better results out of it, so I just stuck with it, and now here I am.”
The funkiness that Backhus speaks of is something that has aided sidearm and submarine pitchers since they first started. He said that his arm angle being so low allows for much more side-to-side movement, rather than a traditional, over-the-top pitcher, whose pitches move more up and down.
While the lower angle gives these types of pitchers an advantage that other pitchers don’t have, it can also present challenges on the mound. Consistency in the strike zone is something that Backhus said he and other sidearm pitchers struggle with at times.
“It’s hard to repeat your delivery a lot,” he said. “Really, delivery is everything. If you can repeat it, it’s a lot easier.”
Backhus has improved his numbers year after year and is likely heading for a major-league debut sooner rather than later.
Throwing sidearm or submarine has its advantages and disadvantages, but the ones who have learned to do it effectively against the best hitters in the world have seen success and longevity at the major-league level. The Diamondbacks have two who promise to have prosperous careers throwing below the horizon.
Category: Arizona Diamondbacks, Cactus League, Top Stories
Tagged: Arizona Diamondbacks MLB Spring Training 2025 Ryan Thompson Sidearm Pitchers
