If the season ended today, the Oakland A's would be the Wild Card representative for the American League, and if the season ended today, hundreds of thousands of season ticket holders across baseball would be pretty pissed off. So those A's have succeeded because of three things: starting pitching, Jack Cust overcoming polio, and more starting pitching. In fact, once ace Rich Harden returns from injury, manager Bob Geren may institute the six-man rotation.
Here's the current rotation in Oakland:
Joe Blanton, 3.88 ERA, 1.35 WHIP
Dana Eveland, 3.67, 1.28
Chad Gaudin, 3.75, 1.19
Greg Smith, 2.54, 1.03
Justin Duchscherer, 2.40, 1.27
Add in Harden and you've got six guys with sub-4.00 ERA's. Perhaps the biggest surprise here is Greg Smith, who, before the season started, was expected to be a mediocre spot starter when someone (read: Rich Harden) got hurt. Smith came to Oakland from Arizona in the Danny Haren trade; five of his six starts have been quality starts and he's struck out 31 batters over 39 innings. It would be hard to bump him from the rotation, as it would be hard to bump any of the four others.
Thing is, the six-man rotation is a red herring. Teams have been talking about using it for years and yet it's never really happened. Why? Rany Jazayerli, in his 2002 article decrying the five-man rotation, used this quote from the great Earl Weaver:
"It is easier to find four starting pitchers than five."
Just like it's easier to find five starting pitchers than six. Starting pitchers are a finicky type. They get hurt, they break down, they lose focus. It's easy to move Justin Duchscherer to the bullpen when Rich Harden comes back. That's what baseball folks call a 'spot starter'. If anything happens in Oakland, it will be closer to a five-man rotation where Smith, Gaudin, and Eveland share the 4 and 5 positions in the rotation, thus keeping their young arms healthy.