What does the number by player mean?

 I understand the ML listed.  But what does the number listed by the player mean?

Like Smith -8.5 vs...

Games 

so in order to cover the 8.5 he would need to win the match something like 6-4 6-3 6-2  

Thanks.

@BrynnyBaby

 Make sure you read the fine print on your selection. There's game spreads for the match (like your example,) but also game spreads per set. Plus there's set spreads

Djokovic -9.5 Games Match

Djokovic -3.5 Games 1st Set

Djokovic -2.5 Sets Match.