Six of the top 10 men on the money-winning list of the pro golf tour are under 30 - and the younger players see this as evidence that the veterans are fading out. Jack Nicklaus disagrees.

The under-30 group in the top 10 includes Tom Watson, Bruce Lietzke, Mark Hayes, Andy Bean, Lanny Wadkins and Tom Purtzer. The 30- or-over group is headed by Nicklaus, followed by Gary Player, Rik Massengale and a 33-year-old "rookie" named Graham Marsh.

Marsh, who won the Sea Island Heritage Classic Sunday by a stroke over Watson, is a first-year man on the American tour. However, the Australian has won 26 tournaments around the world and has competed in three Masters.

Nicklaus doesn't believe this year is any different from other seasons when the unknowns grabbed the early spotlight.

"The young guys are ready to play in the winter and early springs," the 37-year-old Nicklaus noted. "The older players work toward getting their game ready for the four majors (Masters, U.S. and British opens and the PGA). After seven, eight or nine events, the younger guys get stale and tired of golf. You don't hear of too many of them after March."

An even dozen tournaments on the 1977 PGA tour have been completed, starting with the Phoenix Open in early January, which was won by Jerry Pate who surprised everybody last year by winning the U.S. Open at 22. Incidentally, Pate has played in only one tournament since because of tendinitis.

Lietzke and Watson have won two tournaments each. Massengale, Purtzer, Nicklaus, Gary Koch, Bean, Hayes and Marsh have accounted for the other victories.

First-time winners on the tour include Lietzke, Purtzer, Bean and Marsh.

The colleges seem to be the spawning ground for the newer winners on the tour. Lietzke, 25, joined the pro tour in 1975 and began to roll last year when he earned almost $70,000. A graduate of the University of Houston, he was the Texas State Amateur champion in 1971 and was named to the 1973 second-team All-America golf squad.

Lietzke has won $128,380 thus far, second only to Watson's total of $135,185. Lietzke had to pass up several tournaments because of the death of his father. Earlier, he won the Hawaiian Ipen.

Watson is perhaps the best known of the under-30 group. At 27, the native of Kansas City, Mo., already has won four tour events, not including the World Series of Golf and the 1975 British Open. He is a graduate of Stanford.

Purtzer, 25, is one of the two golfing brothers. His older brother, Paul, 28, has yet to win a dollar on the tour. But Tom, who won $27,000 last year, broke through by winning the Los Angeles Open, which accounts for most of his $46,719 this year. He is a graduate of the University of Arizona and won the 1972 Arizona State Amateur championship and the Southwest Open the same year.

Koch, 24, is a University of Florida product and turned pro in 1975 after a brilliant amateur career that saw him win the Florida Open (when he was only 16), the National Junior title in 1970, and the Trans-Mississippi in 1973. He also was a member of two Walker Cup teams. He won his first pro tournament, the Tallahassee Open, in 1976. He won $38,195 last year.

Bean, who was 24 March 13, celebrated his birthday by winning the prestigious Doral-Eastern Open. A 1975 graduate of the University of Florida, he turned pro the same year after figuring prominently in the national amateur ranks.

The lanky (6-foot-4) Bean won the 1974 Eastern Amateur title, the 1975 Dixie Amateur and was a semi finalist in the 1975 U.S. Amateur. He won $10,761 last year but has a current total of $65,408 for the young 1977 season.

Hayes is the nearest thing to Ben Hogan now on the tour. A serious young man of 27 who rarely shows emotion on the golf course, he attended Oklahoma State. He was runner-up in the U.S. Amateur to Gary Cowan in 1971. He made the All-America golf team in 1970 and 1971. Hayes spent two years in the Army, working at the Fort Jackson, S.C., base golf course with Joe Inman, also on the pro tour.

Hayes cracked the $100,000 barrier for the first time last year, accounting for $151,699 in purses. This year, he has won $71,826. He captured the Tournament Players Championship, which gives him a 10-year qualifying exemption.

One of the perennials on the winter tour has been Johnny Miller, who often has had two victories to his credit by the time the Masters rolled around.

But Miller, who still could be counted among the Young Turks because he won't be 30 until April 27, has had a horrible time this year. He has earned exactly $1,173 (he used to spend that much for dinner for his family at a tournament).