By Josh Perry MEDFIELD - Last Friday, Medfield was relentless in its speed of attack to overwhelm Dover-Sherborn. That night it was as though waves of white shirts kept bearing down on the Raiders’ goal, but on Thursday against Xaverian the Warriors chose a more patient style of play. It was just as successful. The Warriors dominated possession of the ball, keeping the Hawks on defense for minutes at a time, and used the extra pass to open shooting lanes. The patience paid off in a 9-4 victory. “We needed to keep the ball out of their middies hands, possess the ball and get good shots,” said Medfield coach John Isaf. “I bet we had 70-30 possession time or pretty close.