Three rounds ago, Otago's place in the playoffs seemed assured.
Losses to Wellington and Central Districts and a rained-off match against Canterbury have left the Volts vulnerable.
Otago's game against Canterbury in Rangiora tomorrow is effectively a quarterfinal.
A big loss could see the Volts drop out of the top four.
Northern Districts would need to beat Auckland and Canterbury would have to record a bonus-point win against Otago for that scenario to unfold.
But a win against Canterbury will enable Otago to secure third place and a home venue for the minor semifinal against Northern Districts.
That game would be played in Queenstown.
Canterbury (11 points) needs the bonus point to leapfrog Otago (15). However, a win would be enough for Canterbury to reach the playoffs if Northern Districts lost to Auckland.
It would then travel to Queenstown to play Otago.
Whatever happens in the last round, Auckland and Central Districts will meet in the major semifinal.
The winner will get direct entry to the final, while the loser will play the winner of the minor semifinal for the right to contest the final.
Central has a two-point buffer at the top of the table over Auckland and can clinch a home venue for the major semifinal with a win against Wellington at the Basin Reserve tomorrow.
If the Stags lose and Auckland beats Northern Districts then the Aces will host the game.
Wellington, the twenty20 champion, is out of contention with one win from seven games.
Otago will not be too focused on the different scenarios, though.
It just needs to concentrate on regaining its form from earlier in the campaign.
The Volts won three of their first four games and were playing some good cricket.
But an off day in Wellington and a stumbling effort with the bat in Dunedin on Sunday have jeopardised their playoff prospects.
Potentially, Otago will field a side for the Canterbury game which boasts four Black Caps - Hamish Rutherford, Mark Craig, Neil Wagner and Jimmy Neesham - plus former Black Caps Jesse Ryder and Aaron Redmond.
That is too much talent to miss out on a spot in the playoffs.
Remaining games
Tomorrow
• Canterbury v Otago, Rangiora
• Wellington v Central Districts, Basin Reserve
• Northern Districts v Auckland, Mt Maunganui
PLAYOFFS
January 24: Qualifier 1 v Qualifier 2 & Qualifier 3 v Qualifier 4
January 28: Loser 1 v 2 v Winner 3 v 4
February 1: Final
