Roger Ebert Explains Star Ratings

From Roger Ebert’s Journal:

I look myself up in Metacritic, which compiles statistics comparing critics, and I find: “On average, this critic grades 8.9 points higher than other critics (0-100 point scale).” Wow. What a pushover. Part of my problem may be caused by conversion of the detested star rating system. I consider 2.5 stars to be thumbs down; they consider 62.5 to be favorable. But let’s not mince words: On average, I do grade higher than other critics.

Now why do I do that? And why, as some readers have observed, did I seem to grade lower in my first 10 or 15 years on the job? I know the answer to that one. When I started, I considered 2.5 stars to be a perfectly acceptable rating for a film I rather liked in certain aspects. Then I started doing the TV show, and ran into another wacky rating system, the binary thumbs. Up or down, which is it?