Unfortunately, no system is foolproof when it comes to knowing whether or not a match has been fixed. However, certain things can serve as red flags that indicate something suspicious is going on, such as large swings in odds or large sums of money suddenly appearing across different bookmakers offering similar lines for a given event. Additionally, always remember that it’s important to remain vigilant against potential attempts at bribery or manipulation – if something doesn’t seem right, then trust your instincts and look into it further!