Two days ago, Joba Chamberlain threw six and 2/3s shut-out innings against the Pittsburgh Pirates and struck out seven of them while walking just one. In the start before that, he threw 5 1/3 one-run innings against the San Diego Padres and struck out nine with 3 free passes. The start before that was on the road against the Houston Astros. He allowed one run over six innings with just two Ks and four walks.
That is 18 innings of work with two earned runs allowed with 18 Ks and six walks. While the walks are a little high, the rest of the numbers scream, "Ace!" Before annointing him a legimtate #1, he has to be considered the best starting pitcher on his own team.
Here are the other four starters. Is he the #1 on the New York Yankees?