4-26-2025 – By Michael Castrignano – @412DoublePlay on X
The Pirates effectively deconstructed Yoshi Yamamoto last night, taking four walks and spraying hits all around the field. Can they do the same to his home country counterpart, Roki Sasaki?
The 23-year old international wunderkind and pre-season Rookie of the Year favorite has had a mixed start to his MLB career – including an emotional viral moment captured from the dugout in his second MLB game.
After spending the last four years pitching in Japan where he was among the most dominant pitchers in the league (2.10 ERA and 0.89 WHIP over 394.2 cumulative innings pitched), Sasaki has looked less dominant in the US, holding a 3.20 ERA through his first 19.2 frames but with a 1.48 WHIP as he’s struggled to keep opposing hitters off the bases.
He has walked as many batters as he’s struck out (16) and all of his FIP, xFIP and SIERA indicate that he’s gotten extremely lucky over these first four outings.
Sasaki doesn’t have the varied pitch mix of Yamamoto but relies on a high-90s 4-seam fastball that approaches triple digits, a mid-80s diving splitter/dragon forkball and a low-80s cutting slider. He appears best able to locate the 4-seam, running in on left handed hitters, while dropping down with the splitter and slider.
His splitter has a ridiculously low spin rate, averaging just over 500 RPM and generating a 45.7% whiff rate while his slider hasn’t yet been hit and has opponents whiffing at a 44.4% clip.
Best chance for the Bucs will be to focus on the elevated fastballs and spit on everything else. His .330 xBA and .612 xSLG against the 4-seam are both well above the actual marks and Sasaki offers the pitch 53% of the time.
If Pirates hitters can pick up the spin – or lack thereof in the case of the splitter – early enough, they should be able to key in on Sasaki’s pitches and get to him the same way they got to Yoshi yesterday.
Steel City Pirates 