Why in dominoes when I play my last one sometimes the opponent gets the score?

Question

Why in dominoes when I play my last one sometimes the opponent gets the score?

Answer 1

Is this Yahoo dominos, that doesn't sound right.

Answer 2

Your opponent wins. You lose. Is this Yahoo! Games you're talking about???

Answer 3

Can you ask that question of someone who is there with you who can see what you are doing and how the play is going?  There must be something you are missing.  See if you can find someone there where you are who can help you figure it out.  You haven't really given enough information for anyone here to understand exactly what is happening.  I hope  you get it sorted.