Michael Mayerle isn’t a caddie. When you get right down to it, he didn’t have much of an interest in golf until a little over a decade ago.

These days, however, you’d have to hunt far and wide to find anyone with a more intimate knowledge of the courses on which the PGA TOUR plays.

Mayerle is the guy in charge of mapping every TOUR venue, utilizing such tools as lasers and GPS coordination – not to mention good, old-fashioned legwork – to create the framework on which ShotLink builds its database and presents it to fans.

“I think I could go through the entire schedule from start to end, every course on the PGA TOUR, and give a description of every hole,” Mayerle said matter-of-factly. “My wife says that’s not a good thing.”

It’s a very good thing, though, for PGA TOUR fans who follow their favorite players online. Or for players and, yes, caddies who use ShotLink’s statistical database to glean information on swing tendencies or other nuggets that might save a crucial stroke at a crucial time.

“They do an amazing job,” said Aaron Spearman, the TOUR’s director of ShotLink productions. “We want to be as accurate as possible, so it’s essential that that mapping be as accurate as possible.”

In a sense, what Mayerle and his team at JMS Geomatics do isn’t much different than a land surveyor trying to determine a property boundary. Except that a golf course involves far more boundaries that come into play during the course of a tournament.

There are natural boundaries, such as lakes and tree lines. Course boundaries include the outlines of greens, fairways and bunkers. Changes in elevation are crucial, especially on putting surfaces. And all must be accurate down to a matter of inches.

Mayerle’s GPS equipment is accurate down to a half-inch. By comparison, the accuracy of the GPS function on most cellphones is about 10 meters; those built into today’s cars is accurate to nearly one meter.

“You can buy a very nice car for what this GPS costs,” Mayerle quipped.

Sometimes the work involves using a robotic total station, a surveying instrument that electronically measures distance and slope on the ground where trees might interfere with GPS readings.

These days, Mayerle’s team also utilizes an increasing database of aerial photography, working with local governments or private outlets to integrate imagery already taken from the air.

“Lake outlines, tree outlines – we can pull those features off aerial photography,” Mayerle said. “But the finer parts – fairways, greens, tees – the TOUR’s accuracy is such that we need to map all those on the ground.”

That means walking the course – every outline, every feature.

To map a tee box, the team member must walk the perimeter of each tee box. He may then walk each edge of the fairway. Each bunker must be circumnavigated, taking care not to lose balance on steep edges. The green must not only be outlined, but walked across in intervals to measure undulation.

“You do that 18 times and you’re done,” said Steve Evans, the TOUR’s senior vice president of information systems. “It’s a process that obviously takes time.”

At each step along the way, a small transmitter on the mapper sends signals back to the GPS unit or robotic total station. Coordinates are recorded every 3 to 5 feet, slowly building the electronic map.

Ground units also are used to fill in anything that can’t be seen from aerial imagery, such as cart paths or waste areas obscured by trees.

Once all the raw mapping data is recorded, Mayerle generates a set of computer-aided drawings (CAD), along with information files that labels each part – left rough, right rough, left and right fairway, etc.

Those files are turned over to ShotLink graphics staff to create the hole maps seen online. “We basically give them the line work and they terrain,” Mayerle said. “They turn it into a pretty picture.”

Mayerle estimates a mapper could end up walking 12 or 13 miles in a day, from early morning until just before sundown. Measuring a course can take anywhere from five to 15 man-days, using crews of two to four people, depending on the topography and available aerial imagery.

When Gil Hanse gave Doral’s Blue Monster a major overhaul two years ago, it had to be remapped completely from the ground because no aerial images had been taken yet. Mapping also took place in January, limiting available daylight and stretching the project to 15 man-days.

“If it had been May, I think we would have gotten it easily down to 10 or 11 days,” Mayerle said.

Sean Howland, the TOUR’s senior manager of ShotLink operations, noted the way a course is laid out also can have a big impact on the time necessary.

“At Firestone, it’s pretty compact space that has a lot of up-and-back,” Howland said. “It’s a very traditional layout. East Lake is sort of the same way. But a resort course, or maybe a TPC course that covers a larger area of land, would be much harder to map.”

Mappers also must be watchful to not interfere with any rounds that may be taking place at the same time.

“We want to be respectful of play,” Mayerle said. “We can’t just show up and own the course. We understand we’re the guest of the course, and you do what you can not to interfere with their day-to-day operations.”

Not that mappers don’t sometimes get surprised by errant shots. Mayerle’s GPS got conked during a mapping at Conway Farms, site of the BMW Championship, and his brother took one on the bounce last year.

“We’ve been lucky, but we’ve had a lot of close calls,” Mayerle said. “You think you’re way out of the way, but you sometimes underestimate how bad some people can be on the golf course.”

Other hazards are more natural. Mayerle has yet to encounter an alligator, but he’s mindful whenever he walks a course in the South. Water moccasins have been spotted.

Preparing to map a Canadian course for a video-game manufacturer, Mayerle read that a woman had been killed a week earlier by a grizzly bear near the course. He made sure to purchase bear spray before setting out.

“Then I remember reading the bear spray [instructions] saying, ‘Not effective past 30 feet,’ ” he recalled. “So I’m asking myself – do I wait?”

Mayerle’s team also does followup work about a month before a tournament, getting precise measurements of fairway widths and green specifications as the course is being set up for the TOUR.

“Even though the superintendent downplays that the outlines don’t change, they do change,” Evans said. “The green will have gotten a little bigger. Grass gets real aggressive and grows outward.”

Asked which course has been toughest to map, the answer came back unanimous – Whistling Straits. The site of last week’s PGA Championship features more than 1,000 bunkers that required being outlined.

“Whistling Straits treated us great, but the amount of work was unbelievable,” Mayerle said. “The next time I go there, I want to play it. I don’t want to map it.”

All things considered, though, the process has become far more streamlined than ShotLink’s early days near the turn of the century, when the TOUR had to do some serious lobbying to get courses to allow mapping crews on their property.

“When we started, we hadn’t even had the name ‘ShotLink,’ ” Evans recalled. “We’d have to tell them, here’s what we’re going to do, here’s how we’re going to use it. We had to find parties to let us on the course and do the work.”

These days, most casual fans now recognize the ShotLink name and the information it provides. Courses are even using the mapping results for their own benefit.

“Superintendents have become pretty intrigued with what we’re doing,” Evans said. “They can take mapping data and compute the square footage of greens or square footage of bunkers. Now they have a much more accurate metric to use as a basis for ordering fertilizer or sand.”

At its core, though, remains the foundation for ShotLink’s tracking function and mountains of statistical information.

“The strokes-gained [categories] are all based on distance data,” Spearman noted, “so that’s one of the major statistics that have come from the data we’ve been able to gather. You can break it down to as much depth as you want.

“It’s essential. We are completely depending on [Meyerle] and his crew.”