South Sydney are among the biggest drifters in NRL betting history with bookmakers pushing the Rabbitohs out to rank outsiders to win the premiership.

The Rabbitohs remain the only winless team after four rounds of the competition following Sunday's limp 20-2 loss to Manly at Brookvale Oval.

Souths started the year aiming for a top four finish and were instilled as $21 premiership fancies, but a string of poor performances has resulted in their odds ballooning in one month to $81, behind 2007 wooden spooners Penrith $67.

"Souths were around a $21 premiership shot at the start of the season, but after Craig Wing's injury, and that inept showing against the Sea Eagles which completed four straight losses, the Rabbitohs have gone for a `betting bath' blowing to $81," said Centrebet spokesman Neil Evans.

"You can hear the fear in coach Jason Taylor's voice, and with on-going injury concerns, Souths are now in wooden spoon contention after just four rounds.

"From $21 to $81 is one of the biggest betting drifts in a month in NRL history."

Fierce rivals Sydney Roosters however are the best-backed team in the NRL after their impressive fortnight with wins over title-favourites Melbourne and last Friday's bashing of the Bulldogs.

The Roosters have firmed from $16 to second favourite $6.50 in just four weeks.

"They were a big mover after trumping the Storm, and now after the demolition of the Bulldogs, they have tumbled in to $6.50 from $9.00 - and punters can't get enough of the tri-colours," Evans said.

"There's more money on the Roosters than any other team, including the well-fancied Melbourne."

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