Complex sentence: Tilden was the World No.1 player for seven years, he won 15 Major singles titles including ten Grand Slams, one World Hard Court Championships and four Pro Slams.
Split into simpler sentences: Tilden was the World No.1 player for seven years. He won 15 Major singles titles including 10 Grand Slams, 1 World Hard Court Championships and 4 Pro Slams.