by his critics and media pundits but also by many fans, that even he would not be able to bring the struggling YZR-M1 up to the level of the hereto all-conquering Honda RC211V. A well-publicised increase in the pace of development of the Honda machine over the winter season fuelled expectation that a Honda RC211V in the hands of riders the calibre of Max Biaggi and Sete Gibernau would have no problem in retaining the World Title for Honda. Meanwhile, Rossi wasn't the only defection Honda had to contend with; Jeremy Burgess (crew chief for Rossi at Honda), along with the majority of his long-established crew, were convinced by Rossi to join him at Yamaha. This was a shrewd move and was cited by Rossi in his autobiography as being instrumental in providing him with the strong basis necessary for launching an attack on the Championship with the YZR-M1. During 2003/2004 winter testing, Yamaha stepped up to the plate by pulling out all the stops in their collaboration with Rossi and Burgess. Through a systematic regime of innovation and testing, they sought to refine the M1's traditionally strong traits such as good braking and quick handling (which impressed Rossi), and marry them with good balance and transition to power. Working closely with Rossi and Burgess, Yamaha engineers under YZR-M1 project leader Koichi Tsuji experimented with a number of engine modifications in an attempt to fix the power delivery, and finally, it was decided to go ahead with a four-valve per cylinder head configuration (as opposed to the earlier five-valve head), with a specially refined cylinder firing order. This turned the straight four-cylinder engine from a traditional "screamer", where the power pulses are spaced equally (every 180 crank degrees) in the four-stroke cycle, into a so-called "long bang" engine where the power pulses are grouped unevenly across the cycle (270-180-90-180). This firing order mimics the constant kinetic energy of a V4 engine while maintaining the desirable engine packaging of a traditional inline four-cylinder. These developments significantly improved the torque characteristics of the engine, and coupled with slight changes to the position of the engine in the chassis, made the M1 much easier to control at the limit of adhesion while exiting corners. After a frantic winter of development and testing, the team showed the world that they had made a significant step in the right direction, when Rossi and the M1