Japan’s Sunwolves have replaced the Western Force in the Australian conference for the revamped Super Rugby competition.

Under the 15-team format for 2018, Australia’s four teams will play each other home and away, intensifying the battle for the all-important conference honours that guarantee a finals berth.

The removal of three teams — the Force and South Africa’s Cheetahs and Southern Kings — has allowed officials to reduce the competition to three conferences of five teams.

The New Zealand conference will again feature the defending champion Crusaders, along with the Blues, Chiefs, Highlanders and Hurricanes.

Argentina’s Jaguares have joined the South African conference with the Bulls, Sharks, Stormers and 2017 runners-up the Lions.

All teams will play 16 matches — eight home and eight away — and have two byes.

The finals will again include eight teams — the three conference winners plus the next highest five sides on the overall ladder.

“It was not an easy decision to reduce the number of teams but a necessary one considering the outputs from the strategic review to date,” SANZAAR chief executive Andy Marinos said upon Thursday’s release of the draw.

“The tournament was not working with 18 teams, the structure was confusing, the outcomes of matches were becoming too predictable and the fans and stakeholders had, through our surveys, voiced their concerns.

“SANZAAR respects that, as a consequence of this, Australia and South Africa have had to make some very hard decisions since our announcement in April that 2018 would revert to 15 teams.

“It is a difficult time for many in this respect particularly those within the affected teams and their fans. We understand the outpouring of disappointment and associated passion shown for these teams.

“To not have done anything would have been irresponsible and would have had a significant impact on the long-term sustainability of the game within our markets.”

The 2018 season will officially kick off on February 17 in South Africa, with the Melbourne Rebels hosting the Queensland Reds on February 23 at AAMI Park in the first Australian derby.

The Brumbies, Australia’s 2017 conference champions, open their season in Tokyo against the Sunwolves on February 24.

The Waratahs host the Stormers in Sydney in their season opener the same day.

In a development to hopefully attract more viewers, only four matches involving Australian teams will kick off between midnight and 3.30am AEST.