Last night I played a tournament match against a guy who is a level 3 LTA coach. On one point I hit a first serve, my opponent made a blocked return which was going about 2-3 feet long and just as his return passes over the baseline, he calls my serve out. A good 3-4 seconds after my serve had landed. Later on in the match he does exactly the same thing. I asked, "Are you sure?". He said he was sure. I said, "It's just that you waited for your return to go out before you called my serve". He said, "Ok, take 2". I refused to take 2 - I'm not even sure why he offered that. Looking this up this morning in the code, principle 17 states: So the ball hadn't actually landed. It was just about to land. So he hadn't broken the code. However, he wasn't calling promptly. I guess the code should say, "All calls should be made within 2 seconds of the ball landing". I think that's reasonable since professional line judges probably call within 0.5 seconds.