The Pinstriped Blog is similar to many other of the popular Yankees blogs in that its author has a bias in favor of sabermetrics, and a strong bias against idiocy. What sets it apart is the identity of the author: Steven Goldman, salaried employee of Yankees Entertainment and Sports, whose paycheck is signed by a certain Mr. Steinbrenner.
It's really interesting on its own merits, as well: there's a great story about Joe "Moon" Harris, a player I'd never heard of. It's Yankee-centric but not exclusive, as he does good analysis of league moves, as well. Two of his six or seven entries so far are about the Devil Rays and their signing of good defensive shortstop Alex S. "career 77 OPS+" Gonzalez to play third base, and the Twins' amazing capacity to do exactly the wrong thing with their players and attempt to "correct them out of their strengths." Like not letting David Ortiz take home run swings, for example.