Andreas Vinciguerra (Sweden)
Age: 18 Ranking: 96 Prize money: $121122
Vinciguerra jumped 541 positions last year to a high of 96 – the third-youngest player to finish in the top 100. The left-hander has yet to win an ATP Tour title, but is an outstanding junior who considers his forehand his best shot, and clay and hard courts his favourite surfaces.
Roger Federer (Switzerland)
Age: 18 Ranking: 64 Prize money: $260 544
Last year saw the Swiss right-hander becoming the youngest player to finish in the top 100, with a highest ranking of 57. He finished 1998 as world number one having won the Wimbledon junior title. At times Federer can look static, but this is largely because he reads the play so well and takes the ball very early.
Xavier Malisse (Belgium)
Age: 19 Ranking: 142 Prize money: $186984
Struggled last year, losing his place in the top 100 despite reaching the final at Delray Beach in May. In 1998, however, the Florida- based Belgian had progressed far enough to take Pete Sampras to a third set in Philadelphia.
Marat Safin (Russia)
Age: 19 Final 1999 ranking: 25 ATP Tour titles: 1 Career prize money: $950 704
This giant Muscovite, brought up on clay in Valencia, climbed to number 23 last year, just behind Hewitt. After winning his first ATP Tour title in Boston by defeating Greg Rusedski, he finished the season by reaching the final of the Paris Indoor Open, where he lost in four sets to Andre Agassi.
Juan Carlos Ferrero (Spain)
Age: 19 Ranking: 43 Titles: 1 Prize money: $215 545
This right-hander made big strides last year, jumping more than 300 positions in the old rankings to number 42, and won his first ATP Tour title in Mallorca on clay in September, beating his fellow Spaniard Alex Corretja.
Nicknamed “Mosquito” and “Chavalito” (little kid), he is one of three teenagers (Safin and Hewitt being the other two) to win titles last year. Reckoned by many senior pros to be the best player to come out of Spain in the past decade.