The America's Cup World Series will be the first opportunity for the teams to go head-to-head in official races, having squared off several times in practice duels in recent weeks.

The first three days follow a double round-robin format, with four races each day. Each team will face their three opponents on two occasions.

The top-ranked team from the round-robin will then face the fourth-best team in one semifinal, with the second- and third-placed teams squaring off in the other.

The winners of each semifinal will face off in the Christmas Cup decider, while the two losers will race in a playoff for third.

For Team New Zealand, it is their only chance to take on the three prospective challengers in official races before the America's Cup match next March.

Luna Rossa, American Magic and INEOS Team UK will then battle it out in the Prada Cup starting in January, which will determine who will compete against the defender Team NZ in the America's Cup match.

Team New Zealand will head into the World Series as favourites, with their second AC75 Te Rehutai impressing early.

They have also showed early superiority in practice races against Luna Rossa in recent weeks.

But American Magic also showed they are a force, with Dean Barker leading the US syndicate to a practice race win over the Kiwis in the last race of the day on Tuesday.

Meanwhile, INEOS Team UK are still somewhat of an unknown, with the team not completing a trial race until Tuesday against the Americans.

Team NZ and Luna Rossa during the second day of practice. Photo / Dean Purcell

However, as Luna Rossa boss Max Sirena said in the first racing-focused America's Cup press conference on Wednesday, don't get carried away with the results just yet.

"The development process will keep going until the end of the Cup," Sirena said.

"Every day there is a different boat in the water. What we see today could change tomorrow.

"Today is not the real level we will see in the coming months.

"You will see a lot of change for us in the coming week and I think everyone else will do the same. We are at the beginning with this boat."