SEATTLE — Two baseball books sitting atop one another on a shelf in Jack Zduriencik’s spring-training office in Peoria, Ariz., serve as an unintentional signpost to the core beliefs of his Mariners’ regime.

One is the current edition of the Bill James Handbook, a tome written by the founder of sabermetrics and filled with the kind of newfangled statistical information not ordinarily seen in newspaper box scores. The other is the most recent Baseball America handbook, where prospects at all levels are judged from a more traditional scouting perspective.

Zduriencik’s first year as general manager of the Mariners has been hailed as the perfect blend of old and new schools of thought in baseball, where ideas from either camp can each share a prime location on the team’s metaphorical bookshelf. To Zduriencik, it’s merely a case of being open to new things in order to gain a crucial edge over 29 other teams looking for similar advantages.

And Zduriencik will need any edge he can get as he heads into 2010 trying to reconcile the raised expectations of an adoring fan base and the payroll restrictions that will add to the challenge of contending in the American League West.

“That’s all it is, just trying to take the next step,” Zduriencik said. “We’re not trying to reinvent the wheel. We’re just trying to be efficient. Because you can sit with any other organization and somebody’s probably trying to tell you they’re doing the same thing. All I know is that we’re doing what we think we need to do.”

In Zduriencik’s case, that meant taking advantage in what was an under-exploited market for defensive skill last year and transforming it into a Mariners team that performed some of the best glovework the game has ever seen. Seattle’s overall team score of +85.5 in Ultimate Zone Rating (UZR) was the best in baseball last season, while Fielding Bible author John Dewan says the 110 defensive runs “saved” by the Mariners was the most since he began tracking such statistics in 2003.

This year, Zduriencik has continued a trend that also sees him looking to exploit potentially undervalued assets off the field as well. He has revamped the team’s strength-training regimen, bringing in Dr. Marcus Elliott from California on a three-year contract to implement a program that all but eliminates traditional weightlifting in favor of exercises based on specific baseball-related movements.

“I can guarantee you, you’re going to see improved on-field results with this,” Elliott said.

The team also began holding yoga classes for players this spring. Last year, Zduriencik imported a new team nutritionist and experimented with programs aimed at improved eye training and oral care.

Mariners assistant GM Jeff Kingston, who came over from the Padres late last season, said the work being done by Zduriencik and his staff reminds him of what his former GM, Kevin Towers, liked to do in San Diego. Towers was known as one of the more progressive GMs in the game and Kingston helped implement Seattle’s yoga program this spring after seeing the Padres do something similar.

“I think there are people here that are maybe more students of the game,” Kingston said of the Mariners. “They’re always looking at and analyzing what other organizations are doing. And in the industry as a whole. Not just in professional baseball, but in the college ranks. In the amateur ranks. There are things we can learn from other people out there.”

Zduriencik said he brought the changes in because they were needed, not in order to make a name for himself.

“When you take over an organization, you’re going to look at everything,” he said. “You’re going to make decisions and you’re going to evaluate everything. And when I sit in this chair, I have to ask ‘Do we have the best minor-league coaches? Do we have the best scouting that we can have? Are we doing the most we can for the players? Are we doing the most we can for employees?’

“So, when you look at the nutritional part of it, it only makes sense. If your guys eat better, they’re going to play better. When you look at the strength and conditioning, you’re just trying to give your player another opportunity.

“So, when we look at how we do things, whether it’s going through sabermetrics, or traditional scouting, in the end, you need to get the best answers you can get so you can make the best quality decision. And I don’t think it’s any different with strength and conditioning, nutrition, or how you approach acquiring players.”

And Mariners fans appear to have bought into this approach with wholehearted fervor. At spring training this year, fans sported buttons stating “In Jack We Trust” — coined after a popular slogan on Web sites and discussion forums used by Mariners supporters who are willing to give Zduriencik the benefit of the doubt when it comes to moves they might not initially comprehend.

That slogan could be put to the test this season.

After taking baseball by storm in December with the sudden acquisitions of starting pitcher Cliff Lee, on-base machine Chone Figgins and middle-of-the-order threat Milton Bradley, the Mariners slammed on the brakes when it came to adding more big-ticket players. Instead, the team opted for under-the-radar types like outfielder Eric Byrnes, first basemen Casey Kotchman and relief pitcher Brandon League.

Perhaps not-so-coincidentally, the team’s payroll heading into the final stretches of spring training remained well below the $99 million spent on last year’s opening-day roster. Conservative estimates had this spring’s Mariners in the low-$90-million range despite reporting a $3.2 million profit for the 2009 season last month to the Washington State Major League Baseball Stadium Public Facilities District.

The Mariners reported a $4.5 million loss for the 2008 season, then cut opening-day payroll last spring from $118 million to $99 million.

Zduriencik declined all comment on his payroll for 2010, citing competitive reasons.

It’s fair to suggest the team is setting aside money in the event Erik Bedard makes a healthy return by June or July. Bedard could earn anywhere from $5 million to $7 million in salary and incentives if he returns before the All-Star break and is productive.

There are also suggestions the team is stockpiling money to take a midseason run at acquiring San Diego Padres first baseman Adrian Gonzalez, a player Zduriencik tried to trade for last July. Gonzalez would provide just the type of boost the slugging-deprived Mariners appear to need coming off one of the worst offensive seasons in baseball last year and perhaps tip the AL West scales if the Mariners can stay in contention.

But the team has to make it to July first.

Even after Lee went down to injury in a rotation that looked shaky at best after the two front-line guys, Zduriencik remained in a bargaining stalemate with unsigned free-agent pitcher Jarrod Washburn.

The pitcher’s agent, Scott Boras, said the Mariners hadn’t gotten back to him after he’d lowered contract demands to $4.5 million.

Boras suggested the Mariners had more money available to them than they were letting on, but did not go into detail.

Nevertheless, the team is leaving itself open to potential criticism if it falls out of contention in 2010 because of pitching or offensive woes while spending less than it did in a profit-making 2009.

It puts even greater emphasis on the “In Jack We Trust” slogan so many fans seem prepared to abide by — for now.

“It’s kind of a unique feeling for me,” Zduriencik said. “Because I really do feel this trust, this friendship with our fan base. I don’t even know how to explain that. But it’s kind of funny when I’m at Safeco Field and I have fans come and ask for an autograph. I consider it an honor. I don’t consider it anything more than I’m flattered that anybody would even think that. If I can make somebody’s day better by giving them a few minutes of my time, then that’s a very important role.”

But the stakes have now been elevated beyond making fans feel good for just one day.

And the challenge for Zduriencik, with so many expectations riding on his shoulders, is to find the magic formula for his team that can make those good feelings last a lifetime.