Complex sentence: As players' levels increase, the diversity of styles decreases slightly, because technically weak styles are quickly eliminated; but, even at the very top of international table tennis, there is a large number of dramatically different styles to be found.
Split into simpler sentences: As players' levels increase, the diversity of styles decreases slightly, because technically weak styles are quickly eliminated. But even at the very top of international table tennis, there is a large number of dramatically different styles to be found.