Complex sentence: The Western Australian cricket team played 31 Twenty20 matches, all of which in the KFC Twenty20 Big Bash, making their debut in the 2005--06 competition.
Split into simpler sentences: The Western Australian cricket team have played 31 Twenty20 matches, all of which in the KFC Twenty20 Big Bash. The team made their Twenty20 their debut in the 2005--06 competition.