The Babe Ruth's bidding history is classic, obvious shill bidding. It's common for shill bidding accounts to have positive feedback for every winning bid. Why? To make the accounts look legit.
I'm not sure that this is a valid indicator, otherwise, I am an unknown and unintended shill bidder. I only bid once on any given auction, usually through an external automatic sniping program, so you are going to see the same bid/winning percentage in my account as here. What you can look at is whether those winning bids were on items from this same seller. That is far more telling than the single bid as a metric.