How Mariners’ pitching pipeline mines MLB draft for under-the-radar arms

In the days leading up to the 2021 MLB draft, Trent Blank was emphatic: The Mariners need to draft Bryan Woo.

How high?

“I know this is going to sound crazy,” Jerry Dipoto, president of baseball ops, remembered Blank telling the Mariners front office. “But this guy would be one-one for me.”

One-one – as in first pick of the first round. That high.

“Yeah,” Dipoto shot back with a laugh, “that does sound crazy.”

Blank, who has held the all-encompassing title of Director of Pitching Strategy for the Mariners since 2020, was so enamored with Woo, that during the first two days of the draft, he regularly called or texted Dipoto, something he’d never done before.

“Did anybody take Woo yet? … Are we going to take Woo?” Blank would ask.

The Mariners knew they wouldn’t need to take Woo on Day 1 of the draft. A right-handed pitcher out of Cal Poly, Woo was considered a midlevel prospect by most – MLB.com didn’t even include him on its list of top 250 prospects – and he’d just had Tommy John elbow reconstruction surgery a few months earlier.

The Mariners, instead, used their first-round pick (No. 12 overall) on high-school catcher Harry Ford, now in Double-A Arkansas and considered by many a top-50 prospect in the game. (With the first overall pick that day – the actual one-one – the Pittsburgh Pirates selected Louisville catcher Henry Davis.)

But Blank, 34, was persistent, as he had been since he’d first watched footage of Woo. And it’s his persistence and his scrupulous eye for talent that has helped the Mariners become one of the MLB’s most prodigious pitching factories, and Blank has had an active role again in preparation for the 2024 MLB draft that starts Sunday.

Each April, after Mariners scouts have compiled their list of amateur pitching prospects, they’ll hand it over to Blank and the Mariners’ High Performance team for a deeper analysis of the prospects’ physical tools.

That list usually includes upward of 150 pitchers, and it’s fairly typical to find Blank – who doubles as a full-time major-league coach for the Mariners, working closely with pitching coach Pete Woodworth to formulate pitching plans for each game – in the Mariners’ hotel or the team airplane evaluating those amateur pitchers using video feeds uploaded on his iPad.

Using pitch-technology numbers and biomechanical information, he’ll assess whether the pitcher might have athletic upside – if they’re “movers,” as he calls them – that the Mariners can tap into.

“He’ll pour through the video,” Dipoto said. “And he’s such a curious guy (that) he will then go find his own favorites who are off the beaten path. He’ll give us the name of a high school kid we’ve never heard of and go, ‘I really like this guy.’”

Which was how Woo ended up highlighted on the Mariners’ draft board three years ago.

On baseball’s 20-to-80 scouting scale, a 50 grade denotes major-league average, a 60 is a “plus” tool and 70 is a “plus-plus” tool. An 80 grade is top of the scale – Aaron Judge’s power, for example.

For the first and only time in his career, Blank gave an 80 grade on Woo’s scouting report, citing the young right-hander’s athleticism and the unique plane of his release point.

“What Bryan has that’s really interesting is, he’s a guy with strength and stability and mobility, all at the same time, with good timing (in his delivery),” Blank said. “You’ve got this unicorn of a mover who’s really strong and mobile. … He popped for us.”

The Mariners eventually selected Woo in sixth round.

They had taken two other pitchers before him: a high school right-hander, Michael Morales, in the third round (he was promoted earlier this month to Class AA) and Texas A&M’s Bryce Miller in the fourth round.

Blank was also high on Miller, giving a scouting grade in the 50-60 range before the draft.

Less than two years after being drafted, Miller and Woo earned big-league promotions last season, and they’re now fixtures in the Mariners’ rotation.

“It’s awesome to see it all play out,” Blank said.

The 24-year-old Woo, 3-1 with a 2.45 ERA in nine starts this season, returned from the injured list Friday for a start against the Angels in Anaheim.

Blank is quick to note that he was hardly the only one in the organization who saw potential in Woo, and hardly the only one involved in scouting pitchers.

At this point, structure is well established: The scouts seek out intriguing arms and get to the know the person, trying to find out if the pitcher has the “growth mindset” the Mariners are looking for.

Blank and the HP team then dig into the pitcher’s athleticism, while Joel Firman, Senior Director of Data Science, and his analytics team dig into how the pitcher is able to manipulate the baseball with each pitch.

“We’ve done very well in the back end of the draft with pitchers,” Dipoto said. “It’s a combination of Trent and the HP department, and Joel Firman and our analytics group. And the thing our scouts do I think better than anybody – we get the right person. Now our scouts will say, ‘That’s a Mariners-type guy,’ meaning (he’s) a hard-worker, attentive, smart; understands modern pitch data; and would be responsive to this type of routine.”

It was that process that helped the Mariners uncover another under-the-radar college arm, Logan Evans, whom they drafted last year in the 12th round. Less than a year later, Evans is now the Mariners’ top pitching prospect and a top-100 prospect overall.

The Mariners will surely be looking for a few more hidden gems when the draft starts Sunday.