LAS VEGAS (AP) _ Annika Sorenstam doesn't mind a good rivalry. Her rivals, though, keep changing.

A few years ago, it was Laura Davies. Then Karrie Webb.

Now, as the season-ending PageNet LPGA Tour Championship begins today, it's rookie sensation Se Ri Pak.

``I think it is fun to have a rivalry,'' Sorenstam said. ``It helps me concentrate on my goals. If I play well, that's all that really matters.''

Playing well hasn't been a problem for Sorenstam this year, unless you count some mediocre performances in the majors for the second year in a row.

She has wrapped up the money title no matter what happens in the $1 million tournament at the Desert Inn Country Club on the Las Vegas Strip, and leads Pak in the standings for her second player of the year award in a row.

With four official rounds left in the season, Sorenstam's scoring average is 69.88, putting her in position to become the first golfer in LPGA history to average under 70 strokes a round for a season.

About all there is left to do is repeat her win her a year ago and add the $215,000 first prize to the $1.07 million she has already won this year.

``So much is at stake in this tournament and you have a chance to make history,'' Sorenstam said. ``I wanted to be the best in everything, so I spent a lot of time working to reach my goals.''

Sorenstam clinched the player of the year award last year on the same Desert Inn course, winning a three-way playoff with a par on the third extra hole.

This year, she is only a third-place finish or better away from winning her second straight player of the year title. Only Pak, with four wins, including two majors, still has a chance to win player of the year.

``It's very special to have a final event where all the awards are on the line,'' Sorenstam said. ``It's just a very special tournament, where you get the best of the best. The venue is quite a fun place in a high-rolling city. And it has a wonderful golf course.''

Pak was just a young qualifier looking forward to her first season on tour when Sorenstam won her last year.

To say the least, it's been quite a debut season for the 21-year-old, who went from medalist in tour qualifying school to win two majors and become a hero in her native South Korea.

``It is a special year,' Pak said.

Even finishing first or second in 13 of the 14 pro tournaments she played in South Korea couldn't prepare Pak for the success she has had in winning the U.S. Open and three other tournaments her first year on the LPGA tour.

``At the start of the season I had to learn many things about the golf course and the country,'' Pak said. ``I thought two to three years to just keep working and practicing.''

Pak has not only had to learn to adapt to a new country, she has had to learn to deal with being a celebrity in her native land.

She was hospitalized earlier this month with the flu and exhaustion in a whirlwind return South Korea, where she received the nation's second highest sports medal from President Kim Dae-jung.

Pak, who is second behind Sorenstam on the money list with winnings of $862,170, came back to play last week in the made-for-television Wendy's Three-Tour Championship outside Las Vegas.