DAVID Tonroe will sacrifice length for accuracy this week in an attempt to help Hong Kong to their first Putra Cup victory in more than three decades. The Hong Kong-born 20-year-old concedes that his ability to propel the ball immense distances off the tee has, as often as not, conspired to work against him. ''There was a stage where I got ridiculously long . . . and ridiculously wild,'' said Tonroe, who has been based in California for the past 16 months attending a Professional Golfers' Career College. ''My game has turned around a lot since I've been in America. My grip is now more orthodox and I have a better posture. I might have lost a little distance, but I am certainly hit the ball straighter,'' he said. Since adopting the changes, Tonroe's results have been impressive. After 10 events on this year's Golden State Tour in California, his consistency has been such that he boasts the lowest scoring average of 71.60. And he hopes his new style will reap dividends this week as Hong Kong bid to win the Carlsberg-sponsored Southeast Asian amateur team championship for the first time since 1961, the tournament's inaugural year. Tonroe returned to the territory on Saturday night in preparation for the nine-nation event which tees-off tomorrow. He joined up with teammates Michael Grant, Ian Hindhaugh and Tang Shu-wah for the first of two practice rounds over the Royal Hong Kong Golf Club's New Course, yesterday. It will be Tonroe's second Putra Cup appearance, having made his debut in the Philippines in 1989, aged 16. This week's tournament holds special significance for Tonroe, who acknowledges it is likely to be his last opportunity to represent Hong Kong at amateur level. After completing his college studies in December, Tonroe plans to travel to the Philippines early in the New Year to take part in the Asian Tour Qualifying School, hoping to win amateur playing rights for the 1994 circuit. If his plans work out he will then spend four months playing the amateur circuit in England and, he hopes, win selection for Hong Kong's 1994 World amateur championships for the Eisenhower Trophy. Then he will consider turning professional. ''This week could well be my last time to play for Hong Kong on home soil. I'd love to do well here and I'm tremendously excited about the tournament,'' he said. South African golfing great Gary Player celebrated his 58th birthday in Hong Kong last night. During his stay in Hong Kong, Player will visit the island of Kau Sai Chau near Sai Kung where he is designing all 36 holes of what will be the territory's first public golfing facility.