SAN FRANCISCO - Barry Bonds won't fully appreciate his decorated career if he never wins a World Series ring.

The San Francisco slugger became the oldest most valuable player of a major North American professional league Monday, winning a record seventh award in the National League.

The 40-year-old left fielder received 24 of 32 first-place votes and 407 points in balloting by the Baseball Writers' Association of America.

"There's a light switch that goes on as soon as they say baseball starts. I change," said Bonds, the MVP for the fourth straight year. "It's that drive for the championship. That one thing not being in my life drives me more than anything. To watch other people win drives me to want to be in that circle. Every year I try to get better."

San Francisco fell six outs short of a championship in the 2002 World Series, losing to Anaheim in seven games.

Bonds, whose season began amid allegations of steroid use, reached two major home run milestones this year, but the Giants failed to make the playoffs in the final weekend.

He finished his 19th major league season with 703 career homers, moving within 11 of Babe Ruth for second all-time. Bonds is expected to reach that mark early next season, then start shooting for home run king Hank Aaron and his 755.

Bonds had 45 homers and 101 RBI in 2004 and also walked 232 times. He demonstrated his durability, playing in 147 games after playing only 130 the previous season, when he dealt with the death of his father and rarely was in the lineup for day games that followed night games.

"I can't explain it," Bonds said of the way he continues to perform year after year. "People are just gifted with a talent. ... Some people are just more fortunate than others."

Los Angeles third baseman Adrian Beltre finished second, getting six first-place votes and 311 points, followed by St. Louis first baseman Albert Pujols with 247 points.

Speaking on a conference call from Beverly Hills, Calif., Bonds repeatedly avoided responding to questions about steroids. He testified last December before a federal grand jury investigating a steroid distribution ring, and has denied using illegal performance-enhancing substances.

He maintained his focus through it all.

"I kind of just walk through it," he said. "I've been dealing with adversity my entire life. ... My dad said, 'As long as they're talking about you, you're doing something right.'"

Bonds is the only baseball player with more than three MVP awards and the only one to win more than two in a row. Pittsburgh's Willie Stargell previously was the oldest baseball MVP, sharing the 1979 NL award at 39½ with Keith Hernandez. Charlie Conerly of the 1958 New York Giants (38) was the oldest NFL MVP, while the oldest NBA and NHL MVPs were both 35: Karl Malone of the 1998-99 Utah Jazz and Herb Gardiner of the 1926-27 Montreal Canadiens.