У вашего броузера проблема в совместимости с HTML5
http://www.fuzzyyellowballs.com/improve-your-forehand-in-45-minutes/
Roger Federer backhands from the side perspective during a practice session at the 2009 BNP Paribas Open in Indian Wells, CA ( http://www.bnpparibasopen.org ). This video is in slow motion.
To learn how to hit backhands like Roger Federer and for more show-motion clips, visit http://www.fuzzyyellowballs.com !