I am certain officials do not give foot faults all the time or that they have a "warning" system.
In this years us open 2014 Federer player Bautista-Agut. Agut was footfaulting over the middle line almost every ad or deuce point (cant remember which). He got called once, and they ignored the official and carried on playing! He then got called again a little while later and looked in shock at the umpire.
I have also seen Tsonga foot fault all the time and rarely get called up on it. Obviously we cannot see the baseline so maybe it is only over the middle.
I remember Karlovic getting foot faulted around 12 times against Murray at Wimbledon.
Hmmmmm....
In this years us open 2014 Federer player Bautista-Agut. Agut was footfaulting over the middle line almost every ad or deuce point (cant remember which). He got called once, and they ignored the official and carried on playing! He then got called again a little while later and looked in shock at the umpire.
I have also seen Tsonga foot fault all the time and rarely get called up on it. Obviously we cannot see the baseline so maybe it is only over the middle.
I remember Karlovic getting foot faulted around 12 times against Murray at Wimbledon.
Hmmmmm....