I'm sure we all know that most pros change racquets every ball change in a match. By my estimates, thats about every 45 minutes or so. My questions are; Do they change racquets that frequently when they practice? Do they hit a little with each racquet before they take it out to a match? (I see some of them unwrapping them, but not all? They mentioned Agassi dropping his tension for the beginning of Wimbledon because of the temperatures, weather. When he goes out for a match with 10 racquets, are they all strung the same? Or would they be strung across a range? (If so, what would the range be?) I apologize if this belongs in the string forum, but I'm more interested in what pros do.