Okay if you look at the specs written on the racket it solves the problem. The pure strike with the white strip is lighter(10.8 ounces ) than the red stripe pure strike (11.3 ounces). this is for the 18/20 pattern.
Hi, i was wondering why some 2014 pure strikes have a red stripe near the bumper guard and throat grommet and some have a white stripe? https://www.lovetennisblog.com/wp-content/uploads/2013/12/71742.jpg https://th.bing.com/th/id/OIP.n_tTVEQe1GAuV3bh5bFyuQHaE6?pid=Api&rs=1
This the second time where in a big match his team gives him a bottle of something which drastically changes his performance. It happened in the finals of Wimbledon when he was playing Federer. Do the officials check the content before Novak receives anything during a match?