[Spicymoose]

The reason you need to vary your play is so that you are not predictable, and cause your opponents to put you on hand ranges as different as possible from what you actually have later on. If you have a hand where you want to {20,60,20}, I think randomly choosing your 3 options based on the percentages is ok, but I think it is better to consciously choose which option, after you have your mixed strategy.

The reason for this is because you currently have some image at the table. Lets say that your image is extremely tight, only bet good hands, never bluff. In this case, you want to people to keep that image, so your likely actions should be more inclined to do things that look weak/tight. Now, if you have something like {50,50,0}, maybe you will be more inclined to fold, to keep your image as is, rather then let people know that you might call down semi-loose. This can only be taken to an extent though, if you are pondering a {10,90,0}, then you can't just automatically fold to keep your image as is.

Basically my point is that when using a mixed strategy, you should be thinking about what your current image is, and where you want your image to go, and have that have at least some influence on your mixed strategy.