Complex sentence: Vladimir Nikolayevich Voltchkov (born April 7,1978) is a Belarusian tennis player, whose greatest achievement was reaching the semifinal at the 2000 Wimbledon, where, as a qualifer, he lost to Pete Sampras in four sets.
Split into simpler sentences: Vladimir Nikolayevich Voltchkov (born April 7,1978) is a Belarusian tennis player. Voltchkov reached the semifinal at the 2000 Wimbledon, where, as a qualifer, he lost to Pete Sampras in four sets.