What's better than one knuckleball starter? Dueling knuckleball starters!

It’s often said “you never know what you’ll see at the ballpark.” Patrons in attendance for Thursday’s 3-1 Tacoma win over El Paso at Cheney Stadium got to see something that hasn’t been confirmed to have occurred in the pro baseball ranks in over 25 years:

Both starting pitchers tossing knuckleballs.

When El Paso's Matt Waldron (on a rehab stint) and Tacoma's Gabe Mosser both toed the slab, it meant a reunion of former teammates from their days in the Padres’ system, but also a chance to see baseball’s equivalent of a rare celestial event twice in one night: the dancing and darting of a knuckleball toward home plate.

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In the pitch-tracking era (since 2008), just 10 players have thrown a knuckleball at the Major League level, while there have been 13 at Triple-A since 2023. The last confirmed instance in which both starting pitchers threw knuckleballs in the same game was on Sept. 15, 2000, when Tim Wakefield (Boston) and Steve Sparks (Detroit) faced off. There was almost another such instance in 2016 between Steven Wright (Boston) and R.A. Dickey (Toronto), but Mother Nature threw everyone a knuckler there.

Mosser, who signed a Minor League free-agent deal with the Mariners in January, was credited with just two knuckleballs (resulting in a groundout and a foul ball), but he said he threw it more frequently than was officially recorded during Thursday's outing. (Occupational hazard: the pitch can be picked up as a sweeper or changeup or splitter due to its odd movement shape and drop.)

Waldron, who used the pitch for 74 percent of his offerings in the big leagues last year with the Padres, officially went to it just 26.2 percent of the time opposite Mosser and got four whiffs on 10 swings. As an added bonus, he threw it harder than last season, up more than 2 mph on average.

While Waldron's knuckler is his bread and butter, the pitch is far from a trick offering for Mosser. While Statcast data has only been available for his repertoire during his time at Triple-A, he's credited with throwing it 65 total times -- and not once has the outcome of balls put in play resulted in an extra-base hit.

"I like to say I can control it, but I can't really," laughed Mosser. "There's little things that I can make it do. I can control it a little bit, but it kind of just has a mind of its own."

Mosser has been throwing the knuckleball since high school. He pocketed the pitch briefly a few years ago, but decided to bring it back in 2024.

"I did get a few cues from Waldron and stuff and we talked about it a little bit," Mosser said, "but his is like a true knuckleball. I hold mine like a true knuckleball, but it kind of has more top spin than his -- [mine] doesn't really shake as much. It's more of the low-spin tumble. It's a little bit different of a pitch, but still the same idea behind it."

The night ended up being a rousing success for both hurlers. Waldron struck out six over four scoreless innings, while Mosser allowed one run over six frames. The two got to catch up during Spring Training with the Padres and Mariners sharing the Peoria Sports Complex but despite spending time together with High-A Fort Wayne in 2021, Double-A San Antonio in ‘22 and El Paso in ‘24, Thursday marked the first time Waldron and Mosser pitched on the same day and essentially shared a mound.

For Waldron, the start was the first step in the right direction back toward San Diego. For Mosser, who was a 27th-round pick in 2018, the outing marked his latest step forward in the quest to join his former teammate at the game's highest level.

"It's definitely been a journey," the 29-year-old said. "Obviously, the end goal is to make the big leagues and be successful in the big leagues, but right now it's more of just pitch by pitch, do what you have to do down here and kind of let it work out itself.

"It's stressful at times, but also, you're living a dream. So you just gotta keep going and live it day by day, moment by moment."

Or even, knuckler by knuckler.