The tennis penalty system is puzzling. Warning are silly and ineffective. All minor penalties should be a point forfeit from the start, no limit to the number. Major penalties a DQ. Similar to the NFL, where, for example, offensive holding is ten yards, every time. You don’t get a warning for the first one, and ejected for the third. (But you do get ejected for a major infraction) In the NBA, a shot clock violation is loss of possession, and a shooting foul is free throws. Every time. Given the way tennis is scored, a point won’t necessarily cost you the match, but it is a lot. Just like ten yards or two free throws.