Updated

Add the score to the list of complicated numbers Padraig Harrington, Justin Leonard, Stewart Cink and others will be calculating at the Reno-Tahoe Open.

For the first time since the 2006 International in Castle Rock, Colo., the modified Stableford will be used in a PGA Tour event. The system designed to reward aggressive play awards 8 points for double eagle, 5 points for eagle, 2 for birdie, zero for par, and minus 1 for bogey and minus 3 for double bogey or worse.

And there's the usual math for the elevation changes and gusty mountain wind on the edge of the Sierra Nevada.

"A lot of calculations have to be done this week," said Harrington, who is making his first appearance at the 7,472-yard Montreux Golf & Country Club in a field that also includes John Daly, Mike Weir, David Duval, Rickey Barnes, Lee Janzen, Rocco Mediate, Stuart Appleby and Chris DiMarco.

"It's a little bit like changing from stroke play to match play. You've got to be a bit more aggressive," said Harrington, who has finished in the top 10 three times this year and is ranked 67th in FedEx Cup points.

"The difference between going from say a par to a birdie is two points. The difference from par to bogey is effectively one point. It's like a shot and a half. Missing birdie putts is a lot worse than missing par putts this week."

It all should make for an exciting finish Sunday on the par 5-18th that stretches to 616 yards but runs downhill, often down wind, and usually is reachable in two.

"You can come down to the last and play the hole OK, make a 5 and some guy four points behind you can pass you," Harrington said. "You never lose a four-shot lead coming down to the last but you could easily lose a four-point lead."

Jana Smoley, director of the 14-year-old tournament, said the course sets up nicely for the different scoring format especially with high risk-reward shots on the final three holes that include the 220-yard, par-3 16th and 464-yard, par-4 17th.

"We like to say black is the new red in Reno," she said. "The highest score wins."

The field includes four players who won the International using the modified Stableford — Lee Janzen (1995), Tom Pernice (2001), Rich Beem (2002) and Rod Pampling (2004).

Like in Colorado, the ball travels anywhere 8 percent to 12 percent farther at the course halfway between Reno and Lake Tahoe than it does at sea level.

Pampling said he "had no clue" the first time he played at the International because he'd never played in the mountains before.

"It was like 'what in the world is going on here?' I was very confused ... The next year, for whatever reason something just clicked," said the Aussie who thinks the trajectory of his shots may have something to do with it.

"My ball flight is not as high as a lot of guys," he said. "Once it's up there, it's anybody's guess how far it's going to go."

Pampling said all the par 5s are reachable in two and a few par 4s can be driven.

"It's going to make it pretty exciting," he said. "I think sometimes guys try to get too aggressive trying to make eagle and instead of making your birdie you might get a par or bogey."

The Reno field includes more than a dozen golfers in the Top 100 of the FedEx Cup rankings — Seung-Yul Noh (38), Spencer Levin (42), John Rollins (44), Troy Matteson (63), Kevin Stadler (68), Pat Perez (70), Dicky Pride (72), J.B. Holmes (74), Chris Kirk (81), Bryce Molder (84), John Merrick (90), John Mallinger (91) and JJ Henry (97).

Scott Piercy, the winner last year, won the Canadian Open in Ontario last week to qualify for the WGC's Bridgestone Invitational in Akron, Ohio. But several other past champs are back in Reno: Notay Begay III, Chris Riley, Will MacKenzie, Parker McLachlin, Matt Bettencourt and Vaughn Taylor, the only two-time winner (2004-05).

The cross-country trip didn't appeal to some who will have to be back in South Carolina next week for the PGA Championship at Kiawah Island. But Harrington said he never considered taking the week off.

"I always play the week before a major," he said. "If I practiced at home I'd get all mixed up. I wouldn't be game competitive. ... The only way I can do that is with a card in my hand worrying about the score."