The fabulous Sydney Roosters are unbeaten after four rounds, as are Melbourne Storm. Melbourne rely on the Big Three of Billy Slater, Cooper Cronk and Cameron Smith for every success. Slater's substitute Cameron Munster is now out for three months, and he will be replaced at five eighth by the Canadian Rylie Jacks. Melbourne will not be at full strength until late June at the earliest. The Roosters have a more balanced talent roster than Melbourne, with dynamic halves Mitchell Pearce and Luke Keary, the brilliant centre Latrell Mitchell, a very reliable full back in Michael Gordon, and a very powerful pack of forwards. The only weakness in the team is Shaun Kenny-Dowell, who is the king of dropsy. The only other challenges to the Roosters, apart from Melbourne, will come from Brisbane Broncos and Canberra Raiders. Whether either of these can beat the Roosters we have yet to see. The top four looks like being Sydney, Melbourne, Brisbane and Canberra, with North Queensland, Cronulla, Penrith and Manly making up the final eight.