Service Rules
Intention of the Service Rules
Nothing seems to generate more arguments and controversy in ping-pong than the service rules. The ITTF are constantly tweaking the service rules in an attempt to give the receiver a better chance of returning the serve. Previously a good server could dominate the game by hiding the contact of the ball, making it nearly impossible for the receiver to read the spin on the ball and make a good return.
Keeping in mind that the intention of the service rules is to give the receiver the ability to see the ball at all times in order to have a fair chance of reading the spin, here is the nutshell version of the service rules. You'll see it's still a pretty big nut though! I've got a more in depth explanation of how to serve legally in table tennis, with diagrams and videos, for those of you who want a bit more help.
Visibility of the Ball During the Service
The ball must always be visible to the receiver throughout the serve - it must never be hidden. This makes it illegal to drop your hand below the table when serving, or put any part of your body between the ball and the receiver when serving. If the receiver can't see the ball at any point, it is a fault. This is why the rules tell the server to get his free arm out of the space between the ball and the net. (Law 2.6.5)
Ball Toss
The ball must be thrown upwards without any spin, and nearly vertically (this means within a few degrees of vertical, not the 45 degrees that some players still believe is acceptable). Umpires are more concerned about having no spin on the ball, then they are about having a perfectly open hand. (Law 2.6.2, Point 10.3.1 HMO)
The ball must rise at least 16cm, which is actually not all that high if you check it out on a ruler. One important thing to note is that it must rise at least 16cm from the hand, so lifting the ball up with your hand to your shoulder, throwing it 2cm high and then hitting it on the way down is not OK! (Law 2.6.2, Point 10.3.1 HMO)
Contact with the Ball
The ball must be on the way down when serving - no hitting it on the way up! (Law 2.6.3, Point 10.4.1 HMO)
The ball must always be above the playing surface, and behind the endline during the service. This includes the time of contact. Note that it is not a requirement that the bat must always be visible, so you can hide the bat under the table if you wish. (Law 2.6.4, Point 10.5.2 HMO)
Warnings and Faults
The umpire does not have to warn a player before calling a fault. This is only done where the umpire is doubtful about the legality of the serve. If the umpire is sure the serve is a fault, he is supposed to call a fault straight away. (Law 2.6.6.1, 2.6.6.2, 2.6.6.3) The belief that they are entitled to a warning is a common mistake among players, even some at the elite level who should know better!
Furthermore, the assistant umpire is not allowed to give service warnings at all, so he will either call fault if he believes the serve is illegal, or say nothing if he thinks the serve is legal or doubtful. (Point 10.6.2 HMO)
If you have been warned for a doubtful serve (eg a forehand serve that was possibly hidden), and then you serve a different type of doubtful serve (eg a backhand serve that may not have risen 16cm from your hand), you do not get another warning. The umpire should call a fault straight away. One warning per match is all you get! (Law 2.6.6.2, Point 10.6.1 HMO)
Obstructing the Ball
An obstruction only occurs if a player touches the ball (with his bat, body or anything he is wearing), when the ball is above the playing surface, or travelling towards the playing surface, and has not yet touched his side of the court. (Law 2.5.8) It is not an obstruction if the ball has passed over the endline, has passed over the sideline going away from the table, or is moving away from the playing surface. (Point 9.7 HMO) So you can be hit by the ball in front of the endline and still not obstruct the ball, provided the ball is not over the playing surface and it is moving away from the table.
The Toss
When the toss is conducted, the winner of the toss has three choices: (1) to serve ; (2) to receive; or (3) to start at a particular end. Once the winner makes his choice, the loser of the toss has the other choice. (Laws 2.13.1, 2.13.2) That means if the winner chooses to serve or receive, the loser of the toss can choose whichever end he wishes to start at. If the winner chooses to start at a particular end, the loser then can choose to serve or receive.
Change of Ends
If a match goes into the final game (ie the 5th game of a best of five), or the 7th game of a best of seven), then the players are supposed to change ends when the first player reaches 5 points. On occasion, the players and umpires will forget to make the change. In this case, the score stays at whatever it is at the time (eg 8-3), the players swap and play continues. The score is not returned to what it was when the first player reached 5 points. (Laws 2.14.2, 2.14.3)
