The TAB has Sonny Bill Williams and the NZ men's sevens teams as second favourites for gold in Rio.

The New Zealand rugby sevens teams at the Rio Olympics have both been tipped to finish in the silver medal position by the TAB.

New Zealand's official betting agency has released its markets for the Rio Olympic sevens tournaments and it has leant heavily on form from the recently completed world series.

The TAB has installed men's series winners Fiji as gold medal favourites ($2.80) in their event, while it has the champion Aussie outfit as warm favourites ($1.95) to become the inaugural women's Olympic tournament winners.

PHOTOSPORT NZ 7s coach Sir Gordon Tietjens has his work cut out for him in Rio if the TAB's picks are anything to go by.

Sir Gordon Tietjens' New Zealand men are rated second favourites ($3.10) in the men's field of 12, just ahead of the South Africans ($3.50) despite their poor finish to the world series that saw them come in third, behind both back-to-back champs Fiji and South Africa.

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Tietjens is adamant he has a squad that can bring back gold from Rio but admits there is going to be an element of luck over the three days in Rio.

"We've got to produce three days of quality rugby, in other words win six games, play particularly well and hopefully get through injury-free," he said.

"Any team, particularly in a sport as demanding as sevens, has to have little bit of luck. If we can get through those games injury-free, that's the luck you need."

Tietjens surprised some by omitting All Black Liam Messam and experienced sevens campaigner Kurt Baker from his squad of 12 for Rio, but believes he has the right mix after seeing key men Joe Webber, Sam Dickson, DJ Forbes, Scott Curry and Augustine Pulu shake off major injuries that sidelined them for all or part of the world series.

He views Blues brothers Akira and Rieko Ioane, double World Cup-winning All Black Sonny Bill Williams and the accomplished Webber as his key strike weapons for Rio.

The TAB sees the men's event as very much a three-way battle for the gold, with Australia rated fourth favourites at a generous $10 to prevail, the USA at $13, Great Britain $15 and the rest at long odds.

The Australian women won three of the five tournaments on the women's world series circuit to break New Zealand's stranglehold, after the Kiwis had won the first three titles.

The TAB have the Aussie women at $1.95 favourites to return from Rio with gold, with New Zealand second favourites at $2.80, ahead of Great Britain ($5.50), Canada ($7) and France ($18).

The New Zealanders failed to win a tournament in the 2015-16 world series, with Canada and France claiming the last two titles after the Aussies had won the first three events.

But NZ women's coach Sean Horan remains quietly confident about his team's prospects in Rio: "The 2015-16 world series is not going to mean a lot," he said after naming his squad for Rio. "It wasn't a priority. Our priority is getting a group of players fit, confident and healthy for three days in August. We've got the players, we've got the game-plan and we've learnt a lot. Plus, we've held back on a few things."

TAB odds for Rio sevens: Men: Fiji $2.80, New Zealand $3.10, South Africa $3.50, Australia $10, USA $13, Great Britain $15, Argentina $31, France $36, Kenya $41, Japan $151, Spain $251, Brazil $501. Women: Australia $1.95, New Zealand $2.80, Great Britain $5.50, Canada $7, France $18, USA $51, Fiji $61, Spain $81, Brazil $101, Japan $151, Kenya $251, Colombia $501.

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