Whitaker's worst result is the fifth placing he achieved in round two. He finished runner-up in round one and fourth in round three and, if he counts only these two results, discarding his result from round two, he is left with 40 points.
Auckland's national enduro champion Chris Birch (KTM) will obviously discard the zero points he received from his no-show in round two, but Birch won both the two rounds he did attend, giving him 50 points and the series lead on countback.
However, on adjusted points, the third, fourth and fifth ranked riders also stand a good chance of winning the Pro class outright.
Tokoroa's Sean Clarke (KTM), Auckland's Liam Draper (Husaberg) and Taupo's Greg De Lautour (Beta) must therefore fancy their chances, especially if they can produce a win at Te Puke on Saturday.
"Last year the Te Puke course was very demanding, probably too demanding and we have made it a little more free-flowing this year. It'll be a real crowd-pleaser," said Clarke, the event organiser as well as one of the leading competitors.
"The series will come down to the last round, which is good. We didn't want any rider simply walking away with it," he said.
The dominant rider in the women's grade this season is Natasha Cairns of Thames. She has been unbeaten in the series so far and another win, or just a top-five result, would give her an unassailable lead.
The Expert grade has developed into a battle between Cambridge's Dylan Yearbury (KTM) and West Melton brothers Hamish MacDonald (Gas Gas) and Angus MacDonald (KTM), while Tokoroa's Vince Steiner (KTM) is heavy favourite to win the Clubmans' grade.
The fifth and final round is the No Way In Hell Extreme Enduro at Oparau over the Easter Weekend, April 20 and 21.