I'm new to this...

I'm MR Platinum -- but most of my stays are at Courtyards or Residence Inns. However I have a trip coming up that puts me in a Renaissance.

What are my chances for a room upgrade? Is there any way to improve the odds? Is there any way to gain insight into the specific odds for a particular location or set of nights? (Sort of like using ITN to pick better flights for 1st class upgrade chances...)