What I found most encouraging from Bryan Woo’s first start

Requested development

This headline is a lie. The thing I was most encouraged by in Bryan Woo’s performance on Friday night was that he was out there at all. And despite being lifted from the game in the fifth inning with “forearm tightness,” he’s listed as the probable starter for this afternoon, so it seems like they weren’t toying with our emotions when they said that pulling him was just precautionary. So I’m letting myself get excited about what Woo has to offer over the rest of the year, which brings me to the subject of this article: his changeup.

Let’s start by zooming out. When he was called into action last June as the eighth starter on the depth chart, it felt like a move of desperation by the Mariners. Woo had only thrown 101 professional innings. 101! And it’s not like he was polished in college either, having tossed just 119 innings at Cal Poly. So even though he had a fastball good enough to survive as an MLB starter, Woo was still pretty raw, never having gotten a real chance to develop his secondaries.

And it showed. Even when you have a special fastball, it’s basically impossible to get through an MLB lineup—especially more than once—without a pitch that looks meaningfully different. That Woo was as good as he was is a testament to just how special his fastball is. And honestly, his fastball is probably good enough to beat same-handed batters.

But without a solid secondary, he was meat against lefties last season, with one of the biggest platoon splits in the game. He struck out 30.4% of righties while walking just 4.2% of them, allowing a wOBA of .221. For context, the lowest wOBA among a qualified hitter last year was Tim Anderson’s .260. But against southpaws, he struck out less than 20% and walked over 12%, allowing a wOBA of .394. The only Mariners hitter with a wOBA that high in the last two decades was 2015 Nelson Cruz.

Woo mostly tried to combat this with a slider and a sweeper. But neither looked that good to me, and the results are propped up by high usage in a pair of outings against the White Sox that don’t look as great now that we know more about the White Sox.

He’ll probably need to hold on to the sweeper and slider, but the pitch I think could really unlock things for him is the changeup. Since he’s got such great ride on his four-seamer, the best complement is probably one that moves in the opposite direction (i.e., down). The speed change will help too, obviously. It’s a similar concept to what we’ve talked about with Logan Gilbert and Bryce Miller’s splitters. Perhaps not incidentally, those guys have pretty similar mechanics to each other, while Woo throws more like Luis Castillo, who’s become more of a fastballer but originally made his name on the cambio.

But his limited development really showed last year as he had trouble commanding the changeup:

That’s a lot of noncompetitive pitches, especially the ones in the righty batter’s box. And consequently, it seemed like he was only throwing the pitch in emergencies. He only rarely threw more than three in a given start, topping five just twice.

So I was very encouraged to see him throw nine of them on Friday night, out of just 62 pitches total. He even seemed comfortable with it in the first time through the order. He didn’t get any whiffs with it, but he did pick up a couple called strikes, including a strike three. I thought the best one he threw was the one that got hit into play, but it got a weak ground ball, exactly what you’re looking for on a changeup.

For the time being, I’m not that worried about the results. Given his limited development, this is an adjustment he’ll have to make at the MLB level, and he’s likely to make mistakes as he figures it out. That’s the short-term price for a long-term improvement. I’d rather he do it in the bigs than waste his fastball in the minors while he works on this, and I think the Mariners agree.

I’m also not that concerned about the results because he only threw nine of them. This article’s a teaser; we’ll come back and take a deeper look after a few more starts. But if he can get to even average results against lefties, Woo could take off, and in theory, the change up is the weapon I like most for that. So I’m thrilled that he’s committed to it, saying, “It’s a pitch that I’ve kind of wanted to throw more. I’ve liked where the action and the command has been at lately, especially like this spring and coming into this year.”