Bullpen sessions aren't always good indicators of success for starting pitchers. But after Joba Chamberlain finished his warmups on Tuesday, both he and Trenton Thunder pitching coach Scott Aldred agreed it was going to be a long night for the Harrisburg Senators.
Chamberlain recorded a career-high 12 strikeouts and combined with two relievers on a five-hitter as the Thunder blanked the Senators, 2-0 at Mercer County Waterfront Park.
The top draft pick by the New York Yankees last year, Chamberlain (3-1) notched his second consecutive double-digit strikeout game, fanning a dozen over six innings while giving up only four singles and a walk. While he had previously relied on a mid-90s fastball and two-tilt slider, the former Nebraska Cornhusker said it was the continued development of his fourth pitch that led to all those whiffs.
"The biggest change with me over the last few games has been my changeup," Chamberlain said. "Scott actually had me change my grip from a four-seamer to a two-seamer. Now I'm getting more sink and fade on it, plus it's a little easier to control, too.
"Once I got into that bullpen, though, I knew I was going to have something good going tonight. Scott and I both looked at each other afterwards and I said, 'Those guys are sure going to have a long night tonight.'"
The Curve (42-39) were unable to hit a fly ball until Javi Herrera skied to right field in the fifth. Chamberlain fanned at least two batters in four different innings and struck out the side twice in the first and third innings.
Chamberlain was fairly economical, ending the sixth with a pitch count in the low 90s. He felt like he had enough left to start the seventh, but the Thunder (51-31) called it a night.
Since May 22, the 21-year-old right-hander has struck out at least seven batters in each of his last nine starts and no fewer than eight in five outings with Trenton. He credits Aldred and catcher P.J. Pilittere for a great deal of his success.
"Scott has been so helpful with me ever since I got here," he said. "The new grip was just the latest thing. He's really helped me locate my fastball better and not overthrow when I'm going for a strikeout.
"My relationship with P.J. has really gotten better with every start, too. He practically knows what pitch I want to throw before I know it. I think I shook him off maybe two or three times. When you see pitchers with great numbers, they often get the credit alone, but coaches and catchers like these really deserve more appreciation."
Justin Pope worked around a base hit in the seventh and Tim Lavigne closed out the win with two hitless innings, striking out two and walking three for his fourth save.
Juan Miranda staked Trenton to a 1-0 lead in the second with a leadoff home run. Alberto Gonzalez tacked on an insurance run in the third with an RBI groundout and leadoff man Brett Gardner singled and walked in four plate appearances.
Frank Diaz went 2-for-4 with a stolen base for Harrisburg, which had more than one baserunner in only two innings. Dee Brown singled and Sheldon Fulse walked in the second, while Fulse and Herrera coaxed free passes in the ninth.
Senators starter Collin Balester (2-7) was the tough-luck loser, giving up two runs on two hits and two walks while striking out six in six innings.
Michael Echan is a contributor to MLB.com. This story was not subject to the approval of the National Association of Professional Baseball Leagues or its clubs.