SEATTLE -- One of the primary focuses of new Mariners general manager Jerry Dipoto upon his arrival in Seattle was to improve the team defensively and make it better-suited for Safeco Field. Bringing in defensive stalwart Leonys Martin to play center field and the athletic Norichika Aoki to play left went a long way toward addressing that need, but the team has literally shifted its emphasis in the infield much more this season as well.
The Mariners were one of the teams that employed the fewest shifts in the American League last year, but that has changed dramatically as new manager Scott Servais and his staff have established defensive shifts on a much-more frequent basis from the very first Cactus League game this spring and will rely heavily on that tactic throughout the regular season.
Convincing his players that defensive shifts were helpful wasn't difficult, Servais said.
"It's actually pretty easy, because they look and see how they're getting defended," Servais said. "A lot of teams in the league are doing it against us. We talked about it early in camp. It was one of our chalk-talk sessions, explaining why we're doing it and the different formations that we'll use, so the players are very comfortable."
When the Mariners play their home opener Friday night at 7:10 p.m. PT against the A's, fans will see several variations on how they infielders line up, depending on the situations and the opposing hitter. Against extreme pull hitters, second baseman Robinson Cano plays a shallow right field or even extends nearly to the right-field line, while third baseman Kyle Seager moves to the shortstop gap with Ketel Marte slides past second.
In other situations, the defenders simply move left or right depending on where the coaches position them.
"There's an optimal, which you kind of roll all the chips in the middle," Servais said. "Then there's kind of a low risk. Sometimes with runners in scoring position, we won't shift quite as much just to cover a little more of the field."
Seager said it's just part of the modern game.
"It's not like it's completely new. We ran some shifts last year," Seager said. "We're shifting a little differently now. We've been more in detail this year with what we're going to do in each situation. You feel very prepared with it.
"You look across baseball and it's done a lot more. It's something that if it makes sense, why not do it? There's been a lot of evidence to support it. When you're hitting against the shift, you definitely notice it. Every once in a while, you try to manipulate a swing, and that plays in your favor defensively."
The shift doesn't always work, of course. Sometimes an opposing hitter will drive a single through the hole where a defender would normally have been stationed, or line a shot to the opposite field against the shift or drop a bunt.
The Mariners employed an extreme shift against Rangers slugger Prince Fielder in the first series, and the lone hit against Felix Hernandez in the Opening Day loss was a flared blooper to shallow left that normally would have been an easy out.
"That was an interesting one," Seager said. "If you don't have a guy on second or third when Fielder is up, then I'm much deeper and that's right to me. But with guys on base like that, you've got to be in a little closer so they can't just get a ridiculous lead. So there are a lot of little interesting things that go on. That's the game. You never know what's going to happen."
But it's about playing the averages, and Servais said the upside has been clear.
The shift paid dividends vs. Fielder in Wednesday's 9-5 win over the Rangers in the bottom of the first inning. With two outs and the bases empty, Cano was in shallow right field while shortstop Marte was playing on the right side of second base. With the count 0-2, starter Wade Miley got Fielder to ground one back to Marte, who handled the play flawlessly to end the frame.
"The pitchers understand that it's a big benefit, but there will be times we get beat by the shift," Servais said. "You just have to weigh the positive vs. the negative. We were way ahead on the shifting outs that we made [in the spring] and being in the right place to make those plays. It's something we'll stay with throughout the year and we'll be pretty aggressive with it."
Greg Johns is a reporter for MLB.com. Follow him on Twitter @GregJohnsMLB and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.