lester has a 2.11 ERA in 76.2 innings in the post season which include a 0.43 ERA in 21 innings of the WS. This is the leverage of Lester. He's also having one of his best regular seasons as a professional. If the Jays did get Lester it would greatly enhance not only their chances of getting to a post season, but actually competing in the post season. How much do you value winning a championship? 2 months of Lester obviously can't compare with 6 years of say Norris, but you still don't know what you're getting with Norris. He could average a 3.4 ERA over that stretch or a 4.1. If you had a crystal ball and he would be a number 4 or 5 more than a number 2...you probably jump all over that trade. Even if you knew he would develop into a number 2 you might make that trade if you felt Stro, Sanchez and Hoffman could all be front of the line guys.
Beane traded a much more projectable short stop than a guy like Norris who is more difficult to project. He did it to win. People on here are gun shy because of how the Dickey trade in particular turned out, but I could go either way on trading for a guy like Lester. I don't think we are going to get Lester because boston probably wants Norris plus and the asking price will be too high. I might consider a one for one Norris or Sanchez for Lester swap though.