The job of F1 commentator is never easy; certainly not as easy as many fans think it is. But this year there is a real challenge for the motormouths – spot the difference between the two Mercedes drivers at speed on a small TV monitor. The problem is that both Lewis Hamilton and Nico Rosberg have a yellow crash helmet and even the design is similar. So telling them apart at distance is going to be really hard. The only way to tell them apart during Grand Prix weekends will be the roll hoops; the T shaped TV camera mounted More…