Complex sentence: As of April 2017 the Leisure Leagues Network had well over 300,000 players, which makes it the biggest independent network of leagues anywhere in the world, with well over 3000 teams playing in competitions in the UK alone.
Split into simpler sentences: As of April 2017 the Leisure Leagues Network had well over 300,000 players. With well over 3000 teams playing in competitions in the UK alone.