World and Olympic champion Sun Yang’s hopes of competing at the Tokyo Games ended on Tuesday when the Court of Arbitration for Sport (CAS) reduced the Chinese swimmer’s ban for doping violations to four years from eight. The shorter sentence, announced by the Swiss-based court in a statement, means Sun will be eligible for the Paris Games in 2024 when he will be 32 years old. The 200 metres freestyle champion was banned after he and members of his entourage were found to have smashed vials containing blood samples taken at an out-of-competition test in September 2018. Sun had questioned the credentials and identity of the testers and has constantly proclaimed his innocence. The 29-year-old, who also won two golds at London 2012, had been boosted by the Swiss Federal Supreme Court last December upholding his challenge against the CAS panel on grounds that a judge had exhibited possible bias …