By Patrick Appel
Paul Zehr is writing a book on whether one could train to become Batman (the most human of superheros). Zehr recently sat down with Scientific American. His answer to a question about the length of Batman's career:

Keep in mind that being Batman means never losing: If you look at consecutive events where professional fighters have to defend their titlesMuhammad Ali, George Foreman, Ultimate Fightersthe longest period you're going to find is about two to three years. That dovetails nicely with the average career for NFL running backs. It's about three years. (That's the statistic I got from the NFL Players Association Web site.) The point is, it's not very long. It's really hard to become Batman in the first place, and it's hard to maintain it when you get there.

On a related note, Dark Knight is having a big weekend.

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