I have been looking at the seating charts for my United JFK-LHR-JFK flights and there is something I don't understand. My JFK-LHR flight is a morning flight near the end of June. Almost all of the seats on the left side of Business Class are already reserved, but the right side of the plane is almost empty. My LHR-JFK flight is an early evening flight at the beginning of July. Almost all of the seats on the right side of Business class are reserved, but the left side is almost empty. Is there a reason for this? I would appreciate the benefit of your experience. Thank you.