And after one fairly disjointed step forward in his first start with the new motion, Walker looked like a man unleashed against the Angels as he allowed just three singles with no walks and 11 strikeouts in a dominant performance.
"Anytime you make changes like that, especially at this time of year, there's a risk, but the reward is what we all saw [Tuesday night]," Stottlemyre said. "He got a handle on it and it translated into his pitches and execution. His stuff was better. He had a better breaking ball, tighter spin on it. Had more bottom to his split. His fastball command was outstanding. I was so happy and proud."
Stottlemyre, who joined the Mariners this season to work with new manager Scott Servais, said Walker came to him after giving up three home runs and six runs in two-thirds of an inning against the Angels on Aug. 2 and said he was ready to do whatever needed to be done.
"He was down," Stottlemyre said. "It's hard to admit you're lost and searching, but he was. He has a lot of pride and he sat on that bench after getting his butt kicked and buried his head. As a coach, you don't ever like to see that. But he needed that. He needed to go through that.
"That was the turning point. At that point, he decided it was time to make some adjustments and changes. And look, these are drastic ones. These are not easy. At the tail end of the season for a team that is possibly in a playoff run, to go out and kind of create a new delivery is not easy to do."
Walker looked at video of pitchers like Jake Arrieta and Roger Clemens. He looked at video of himself. He practiced his new motion in the mirror, practiced it while playing catch, practiced it in the bullpen. And finally, he said, it clicked about three days before he faced the Angels again.
"We really worked," Walker said. "Mel and I got after it. He just told me, 'OK, we have to make a change. We have to do it. It'll help in the long run.'"
Stottlemyre said it was the biggest adjustment he's ever asked a pitcher to make in midseason and credited Walker's athleticism with making it possible.
"This is something that when I laid my eyes on him over the course of the winter, just looking at how he worked, I envisioned him getting to this," Stottlemyre said. "With the nice run he had last year and some spots here and there where he was throwing the ball good this year, we just started those conversations and some of those changes I thought needed to take place. I'd say it was about six weeks into the season. And now here we are.
"The one thing about him, he's a young kid. He has little pitching experience. But he's a heck of an athlete and athletes make adjustments and changes easier than the ones that aren't athletic. It's a constant battle to make changes and this was a big one. So give the credit to him. And we're not done."
• First baseman Adam Lind was out of the lineup for a third straight game Wednesday due to a sprained right index finger and Servais said he's still a few days away from being able to grip the bat well enough to play. Rookie Dan Vogelbach got his second career start in Lind's place.
• Though Servais indicated a week ago that newly acquired outfielder Ben Gamel would get quite a bit of playing time in the remaining weeks, Norichika Aoki and Seth Smith have been hitting so well that they've been getting most of the recent play. Aoki and Smith both homered in Tuesday night's win.
"Smitty has certainly turned it up and Nori has been great since he's been back," Servais said. "There's still plenty of time to get Gamel in there, but when those guys are going as good as they are, they're really kind of leading catalysts of our offense and it's a huge difference. It's what we saw through May when we were playing really well. It was really driven by the pieces around our core, which is Aoki and Smitty and guys like Leonys [Martin] at the bottom."