you will hear both sides but i would say it is when getting key numbers, like -2.5 if you like the fav or +3.5 if you like the dog. In the end your getting screwed by the juice one way or another.
half a point can make all the difference but in the case of -7.5 or -8. I would not buy a half pt from -8 to -7.5. losing/winning by 8 is not that common so I would roll the dice and if they win by 8 it's a push you get your money back.
