MLB Analytics

So I got into an argument with a Yankees fan (as one does). He said, “Yankees are still higher than Toronto in the power rankings,” and... it didn't sit right with me. Sure, at the moment he said it, he was right, but I KNEW for a fact that Toronto had been higher most season. That stuck in my head way too long, so I decided to find out for real. When did Toronto actually pass the Yankees? Are power rankings even that reliable? And while I was at it, could I figure out how to measure a team's real performance - maybe even predict what's coming next?