Imai’s big start for Giants

Tatsuya Imai earned his first big‑league victory in only his second major‑league start, striking out nine batters across 5 2/3 scoreless innings as the Houston Astros routed the Oakland Athletics 11–0 on April 4, 2026. (MLB.com ) He chased hitters with a heavy four‑seam fastball and a late‑dropping splitter that teammates and scouts had been talking about all spring. (Baseball Savant ) Imai’s outing cleaned up the rough impression he left in his debut. In his first big‑league appearance on March 29 he left early after struggling with control and admitted he felt nervous in the new environment. (Houston Chronicle ) Before he ever set foot on an MLB mound, Imai was a proven starter in Japan’s Nippon Professional Baseball with the Saitama Seibu Lions. He posted a 1.92 ERA and 178 strikeouts with the Lions in 2025, and he arrived in Houston after a brief posting window and a multi‑year contract that includes player opt‑outs. (MLB.com ) The gear that made him a star in Japan showed up in Houston. Statcast lists his primary mix as a mid‑90s four‑seam, a hard slider in the upper‑80s and a splitter in the mid‑80s, with the four‑seam used about half the time and the slider roughly a third. Those offerings produced whiffs and weak contact in short order. (Baseball Savant ) Reports from spring training had flagged the splitter in particular. Teammates described its late drop as unlike anything they had seen, and Houston staffers said it pairs unusually well with his fastball to create swing‑and‑miss opportunities. (Sports Illustrated ) Nine strikeouts in 5 2/3 innings is a raw number and a cast‑iron signal. It works out to about a 14.3 strikeouts‑per‑nine‑innings rate for the outing, a pace that shows his stuff can retire big‑league hitters without relying on defense. Statcast also shows a high whiff rate on his breaking stuff and a profile that produced mostly grounders and weak contact in this game. (MLB.com ) (Baseball Savant ) The start is not a finished statement so much as a translation check. Moving from NPB to MLB changes the baseball, the strike zone tendencies and the depth of scouting reports. Imai had a shaky launch in his debut but adjusted quickly enough to dominate this time, which suggests his pitch shapes and sequencing can hold up against major‑league hitters. (Houston Chronicle ) His line against Oakland — 5 2/3 innings, three hits, three walks, nine strikeouts, no runs allowed — is the concrete result that will shape the conversation next time he takes the mound. (MLB.com )