He has played 851 singles matches on the ATP tour, won 15 titles and banked US$12.7 million ($15.38 million) in career prizemoney and in 2002 was ranked No2 in the world.
There have also been some big slumps and in 2011 he was a lowly 896 after a couple of seasons wrecked by injury. His resurgence in 2012 saw him named ATP Comeback Player of the Year for a second time.
"Maturity helps with everything in life," he said. "When you've been on the road for quite a bit, you know what works for you and what doesn't. You know how you feel and what you've done in the past to prepare yourself.
"Sometimes it's mind boggling if you think about the fact that you're playing against a 19- or 20-year-old and I'm 15 years older than this kid. That's crazy. But it is what it is. You try to use your experience.
"You can have as much experience and knowledge about the game as you want, but sometimes you can't execute the shots. Maybe your legs are not as quick as you want them to be, you step too slow or you go for the wrong shots.
"It's dangerous also, the more you know about the game, the more options you have and the tougher it is. For players who can change things around, they think too much at times."
This year marks his fourth visit to the Heineken Open and he will hope to go one better than in 1999 when he was a beaten finalist. APNZ