GLENDALE, Ariz. -- In the last 15 years, the Dodgers have had 10 hitting coaches.

Mark McGwire makes 11.

That's a coaching revolving door that even the late Yankees owner George Steinbrenner would admire. The Dodgers tried a Hall of Famer (Eddie Murray) as hitting coach and a former player who never reached the Major Leagues (Jeff Pentland). They tried a former villain (Jack Clark '85) and a Yankees legend they later promoted to manager (Don Mattingly).

And now they've turned to McGwire to duplicate the success he had in St. Louis, where he adapted equally to a proven masher like Albert Pujols and youngsters like David Freese, Allen Craig and new Dodger Skip Schumaker.

McGwire follows Dave Hansen, who was not retained after the Dodgers' offense finished 13th in runs scored last year, a season in which the best hitter (Matt Kemp) was injured and an in-season influx of All-Stars made little impact. McGwire has the advantage of a loaded lineup to work with from the get-go, featuring five All-Stars.

One of his early projects is to figure out why Andre Ethier has forgotten how to hit left-handed pitching. Last year, Ethier hit .284 on the season, but .222 against lefties and 103 points higher against righties and a 339-point differential in OPS against right-handers versus left-handers.

McGwire, who minimizes mechanics and focuses on approach, studied all Dodgers hitters during the offseason and came to Spring Training with an analysis of Ethier that will leave stat crunchers gasping.

"It's not as bad as you guys think it is," McGwire said of Ethier's variance. "It's not like he hasn't had some success against them."

In fact, Ethier hit .351 and had an .846 OPS in his rookie season of 2006 and .279/.716 in 2007. In 2008, the disparity arose, as he hit 83 points higher vs. right-handers and his slugging percentage against lefties plummeted.

That's the way it's been for the last four years, including the two full seasons that Mattingly was Ethier's hitting coach.

McGwire said his approach to Ethier's approach is simple: reinforce his past success.

"There is no reason why he can't have the success he's had his first three or four years against left-handers," said McGwire. "I watched him hit off Donnie and it was real good, what I saw. It's about mindset, confidence and about reinforcing positive things. He's a guy who puts his work in and he's going to be a lot better, I really believe that."

McGwire said his style is long on communication and simplification.

"There's so much failure and negativity that it's all about positive reinforcement, about the mental side of the game. You can do mechanics and the physical all you want, but it's about a game plan and watching what's happening. It's all about the mindset. It's a beautiful thing to watch them think and use their head rather than be mechanical. When you start thinking about your hands and feet, you're done."

Ethier said he already likes McGwire "a lot" because he's "willing to put in the extra work" to learn what makes you tick. With some hitting coaches, it's their way or you're on your own. But McGwire, Ethier said, did research to learn his tendencies.

"With me, it's about pitch recognition and being patient," said Ethier, who starts the first year of a five-year, $85 million contract extension signed last summer. "At the same time, on the mental side, I have to be confident to go up and know how I want to execute and stick with the approach."

Ethier's struggles have been monumental when facing situational lefties brought in specifically to get him out in late-inning jams. For example, he's 1-for-10 against Giants lefty Javier Lopez, 1-for-10 with seven strikeouts against Colorado's Rex Brothers, 2-for-13 with six strikeouts against San Diego's Joe Thatcher, 0-for-6 against former teammate Randy Choate.

"That's one thing we're working on," said Ethier. "There's one guy for that game, that's his job, and their shuffling everything for him to face me in that situation. The game has evolved to that and I need to become more successful in that situation, more on the approach side of the at-bat, the mental aspect of it."

Having been a hitting coach, Mattingly knows there will be an adjustment for hitters to coach, even when the coach has the physical and statistical presence of a McGwire.

"It takes a while to build that trust with them and for them to know who you are," said Mattingly. "But I knew right away when I talked to him. You watch St. Louis' approach, that tells you something. The way their young guys improved tells you something. And A.J. [Ellis] saying that they're tough to face as the game goes on tells you something. It all goes back to him."

Ideally, McGwire said, the hitter becomes his own hitting coach, citing Adrian Gonzalez, who knows his swing and its flaws. He said many of today's players spend too much time on the laptop watching their swing when they could be watching how the opposing pitcher gets them out. More often than not, the hitter gets himself out.

"You can look at yourself all you want, and you can make stuff up, but look what you're swinging at. King Kong can't hit that," McGwire said. "But it's also OK to swing and miss, or the guy had nasty stuff and got you out. It's OK, turn the page, you'll get yours."