What determines the rating of a table tennis ball? I know there are several different star ratings. The ratings go from 1 star to 4 star. I think there maybe a 5 star ball.
What factors determine the ball's star rating?
I've played with 1, 2 and 3 star balls. I'm not sure 4 or 5 star exist. Some companies have brands that they say are 4-star but they aren't actually rated above 3-star because a 3 star rating means the highest quality ball possible. The factors that go into the rating are durability, visibility of the seam on the ball, balance of the ball and elasticity. The legal colors to play with are white and orange, though you can find all kinds of different colors in most sporting goods stores. Typically 1 or 2 star balls are bought in bulk (packs of 100 or 200) and used for rallying or practice - and the 3 star balls are saved for real competition (matches). You'll notice that after ping pong balls see some action, they slowly lose some of the smooth matte finish when they are new out of the package.
According to this site, 3 star ball are the ones that meet the ITTF's competition ball specifications for quality and consistency. 1 and 2 star balls are often the discarded balls from a 3 star production run.
When you buy balls from a department store the balls will usually be all official tournament size, these balls are often two star balls, however the three star balls are official size and weight, and you will notice that when playing with them that the two star balls do not bounce as well. So next time you're playing welts or beer pong, make sure you aren't using your tournament quality balls, save them for official play.