Maybe Kvan get's stronger as the game wears on?
Maybe Kvan looses control as the game wears on? Loss of control can lead to uncontrolled wild swings..
Maybe lead tape can be added after a specific number of points played?
I definitely might be loosing focus after the initial couple of minutes, but I doubt that small loss of focus would result in a difference of racquet feel. Yeah, as I said, I'm planing on experimenting with some lead.