Foot faults are much more common than most players realize. If it is obvious call your opponent out and see how easily it is to win some free points because they will be rattled and start making serve errors. At the club/recreational tournament level I have seen many players at ALL levels of experience consistently foot fault on each serve and not be called out. I have seen foot faults as egregious as an entire (yes - entire not partial) foot land well inside the baseline WELL before contact with the ball. In this case, a singles opponent can easily see this if they are watching out for it. The more common foot fault is the foot that clearly touches the baseline WELL before the ball is struck. Those are much more difficult to call in singles and the rules say that if in doubt give the benefit to your opponent. In other words, don't call it. I CHALLENGE EACH OF YOU TO WATCH YOUR OPPONENT AND I GUARANTEE THAT AT LEAST ONE OF YOU READING THIS POST WILL MAKE THIS DISCOVERY.