Get a Hartford Courant subscription for less than 29 cents per day

Juan Martin Del Potro

No. 1 Djokovic, No. 2 Federer easily reach US Open final

At 34, and more than three years removed from his most recent Grand Slam title, Roger Federer arrived at this U.S. Open with some changes in store.

There's his much-discussed "SABR" — "Sneak Attack By Roger" — tactic, in which he half-volleys the occasional second-serve return. He skipped a hard-court tuneup tournament last month, choosing to rest and prepare. And he's now completely comfortable with the larger racket head he had experimented with off and on in the past.

Add it all up, and he might just be playing as well as ever, which is saying something for a guy that owns a record 17 major titles.

Federer moved into his first U.S....