The latest development over the last few years has been the plethora of polyester strings, in a category created by Luxilon Big Banger. This string was originally used by a number of PRO's looking for durability and tension retention during matches. These types of strings are all the rage at the moment as they provide the optimum level of power, control and spin (a la Nadal). The majority of people now use the polyesters as a HYBRID by combining with a Synthetic gut or multifilament, but some chronic string breakers use them on their own. Watch out for that impact on the arm though, especially in the case of youngsters. We would also recommend reducing the tension when stringing with polyesters on the mains and crosses. Luxilon still make the widest variety of polyester strings, with a number of different offshoots of colour, texture and guage. Babolat make the best selling Pro Hurricane, which is incredibly durable and playable. Federer uses a Hybrid Luxilon/Wilson mixture called Champions Choice, which is basically Luxilon Alu Power rough PLUS Natural Gut.