Serena matches her easiest win over Venus in US Open rout

NEW YORK — Serena Williams kept booming big shots for winners, never allowing herself to feel sorry for the overmatched player on the other side.So what if it happened to be her big sister?The Williams sisters, long ago in careers that have spanned 20 years and 30 meetings as professionals, learned they had to view each other only as opponents — and in Serena's eyes, Venus is the best one she's ever played."Even though it's difficult, especially for me," Serena said, "we just do the