I was at the Indian Wells Tennis Garden for the BNP Paribas Open and took the following photo of center court.

enter image description here

The end lines appear to be thicker than the other lines (including the service line). My questions are:

  1. Is this an optical illusion or standard for tennis courts? Growing up playing tennis, I don't remember this being the case, but my memory may be poor on this detail.
  2. If standard, is this because tennis is filmed from the ends, and the parallax would make the lines look too thin? Or is there some other reason?

2 Answers 2


It is not an optical illusion - some courts have a thicker baseline painted because it is supposed to

1) make it a little easier for the people calling the lines to see whether the ball was in or out. Not all courts have a thicker baseline, but it is more common among courts used for professional matches. Thus, your standard public park / recreational courts are not likely to have a thicker baseline.

2) It typically helps the players see the baseline opposite them a little easier - since it is the line farthest from the players viewing position.

Also - it is mentioned in the specifications for building a tennis court. See Page 9 here:

2.5.1 Court Lines.

The centre service line and centre mark line must be 50mm wide. All other lines except the base line may be 25mm-50mm wide. The base line may be 25mm-100mm wide.

Personally I have played on courts with both a standard thickness base line and a 100mm thick baseline and it has not made much difference to me as far as visibility is concerned.

Here is an additional page that is a good reference on court dimensions and line widths.


The real reason for the thicker baselines is perspective for the TV angles, making them look the same-width as the side lines from the back of the court.

If they were not thicker, you would barely be able to see the baseline from most TV angles.

  • 1
    Evidence? The rules allowed a 4" baseline in 1949, if not all the way back to Major Wingfield.
    – user207421
    Commented Jul 2, 2016 at 5:24

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