Kyle Nelson had no idea a few months of playing catch with his older brother Dylan would help revitalize his MLB career, but he knew he could count on him.

“He’s really one of the smartest baseball minds I’ve been around,” Kyle said about his brother. “He taught me basically how to pitch. He taught me how to throw a slider.”

When the lockout froze the MLB offseason in early December, players lost access to their coaches and facilities. So Kyle went home to San Francisco, where he and Dylan met five or six days per week to work on his pitching arsenal.

“This dude was a monk,” Dylan said.

Kyle would go to the gym and complete his normal morning routine while Dylan was at work. In the afternoon, the brothers would meet at a local ballpark, and Kyle would follow his scheduled throwing program with Dylan as his catcher. One day, they focused on glove-side fastballs. The next day, sliders down in the zone. By the time the lockout ended in March, they had been doing this for around three months — and Kyle was a different pitcher.

Coming off a down-year in Cleveland that saw him post a 9.31 ERA in 10 big-league appearances and a 6.66 ERA in 25 Triple-A appearances, Kyle knew he needed to make some changes. 

With the help of his brother — and a revamped slider — he is now having the best season of his career in Arizona, to the tune of a 2.00 ERA, 1.07 WHIP and a .216 opponent batting average in 31 appearances.

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A quick glance at Nelson’s numbers from last season reveals a glaring problem: too many walks. Nelson walked 28 in a total of 35 ⅓ innings between Triple-A and the majors. Every major-league pitcher has his kryptonite, but for Nelson, an excess of walks generally was not it.

“Throughout the course of my career, I’ve had pretty good command,” Nelson said. “I just had a weird season and a big struggle with it kind of for the first time.

“It had a lot to do with my performance not being great last year.”

When the Diamondbacks claimed Nelson off waivers in November of 2021, he was told that lack of command might not have been the problem.

“My percentage of pitches in certain zones from last year and all years prior was actually almost identical,” Nelson said.

What changed was the number of swings on those pitches, particularly his slider. And Nelson had an answer for that part, too.

“My slider movement got more horizontal,” Nelson said. “It was moving a little bit earlier, getting more break, and guys were able to hold off on it.”

Interestingly, the whiff rate on Nelson’s slider last year was 33.3 percent, almost identical to this year’s 33.6 percent. That means when opposing hitters swing, they are missing with essentially the exact same frequency as last year. 

However, the chase rate on the pitch has increased from 19.4 percent last year to 41.5 percent this year. In other words, when Nelson throws his slider out of the strike zone — which he does more than half the time — opposing hitters are swinging at it more than twice as often as they did last year.

The end result is remarkable: Although Nelson is throwing fewer pitches in the strike zone than he did last year, his walk rate is less than half of what it was a year ago.

So, how did he do it? After an extensive film study, Nelson came to the conclusion that, when he was at his best, his slider was more vertically-oriented than the sweeping version he threw in 2021. He sought to make his slider more vertically-oriented, cutting out some of the early horizontal movement that was making the pitch too easy to identify. He’s also throwing the slider harder at 84.2 mph, up from 82.5 mph last year.

“My number one concern is how long from when [my slider] leaves my hand…does it stay on that plane,” Nelson said. “The harder I throw it, the longer it looks like a fastball.”

Now, why all this talk about the slider? Nelson is part of a growing number of pitchers whose primary pitch is a breaking ball. He has thrown his slider 64.1 percent of the time this season. After dropping a cutter that muddied his pitch mix last year, his only other offering is a four-seam fastball.

Pitching coach Brent Strom said he might have “overcooked” the slider a bit, complimenting his effective fastball that may warrant more frequent use. But there is no question the simplified two pitch-mix has been effective.

“They complement each other,” Strom said. “You have one pitch that has a little jump to it, the other one going down. [It] creates some separation.”

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Dylan was never there to tell Kyle what to do, but he did set a high bar.

“[Kyle] would tell me what he was doing and I would, as an older brother, tell him if he did it or not,” Dylan said. “If he was telling me he was trying to tighten [his slider] up a little bit…and he throws a big loopy one, I’m gonna tell him it was a big loopy one.”

Blunt honesty — like any good older brother would do.

Dylan was more than an honest critic, though. He was a sounding board, an encourager and a more adept baseball mind that he gives himself credit for. As Kyle overhauled his slider during the lockout months, Dylan was there every step of the way, offering feedback and helping in whatever way he could.

Eventually, March rolled around, the lockout ended and the long-awaited Cactus League commenced. Kyle made a strong impression over five spring training appearances, allowing no runs and three hits over 4 ⅓ innings with six strikeouts and just one walk. Somehow, he might have made an even stronger impression during his first meeting with manager Torey Lovullo.

“He was vulnerable. He shared some of the things that were preventing him from being what he thought would be a really good big-leaguer.” Lovullo said. “That [is] very uncommon. You don’t necessarily hear that, that insecurity or that vulnerability with a player. But I think when you get to that level of your career, and you know who you are and you know what your limitations are, you can attack them.”

Kyle narrowly missed out on a spot on the Opening Day roster, losing the job to veteran reliever Oliver Pérez — for the second consecutive year. Yes, Pérez blocked Kyle in Cleveland last year, too.

Nonetheless, after just two appearances with Triple-A Reno, Nelson got the call to the majors, and he has stuck as one of the team’s most reliable relievers.

“It’s been a story of perseverance for him,” Lovullo said. “He didn’t start the year with us in the big leagues, and once he got here, he’s just been very consistent.”

Of course, Kyle is not a finished product. His peripheral numbers suggest he may have more work to do maintain a 2.00 ERA in the long run. Strom suggested that Kyle could try to revamp his horizontally-oriented slider for use against lefties.

With a world-class pitching coach at his brother’s fingertips, Dylan doesn’t offer much pure pitching advice during his conversations with Kyle.

“I have so much respect for those guys at that level…and just the way that they can play the game and do it every day,” Dylan said. “I don’t know how to get Brandon Crawford out.

“I think I used up all my tips by 16,” Dylan said with a chuckle. “[Kyle] was like, ‘I’m done, dude. I’m 12. I just threw a no-hitter. You can’t tell me anything.’ [I was] like, ‘Yeah, I guess you’re right.’”

Pitching in the majors is about more than pitch shapes, release points and arm angles, though. It is a mental battle. On that, Dylan offers support in whatever way he can.

“What I will talk to him about is…what kind of preparation we did or what our mental state was,” Dylan said. “Or even when we came in out of the ‘pen, what were we thinking about?”

By all indications, Kyle has been winning those mental battles more often than not this season.

“He’s on the attack,” Lovullo said. “I can feel that. I can feel his presence when he takes the mound.”

With the 15th-best ERA among National League relievers (minimum 20 innings), it is hard to ask for much more from the D-backs’ lefty. It’s amazing what playing catch with your brother for an offseason can do.

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Top photo: Eric Hartline/USA TODAY Sports