Nicholson has an uncatchable 55 points in the six-part Classic series of four-star premier events, after three wins and a third placing - and he skipped the Adelaide leg last November - with strong rival, Britain's William Fox-Pitt on 36 and fellow New Zealander, and Badminton winner, Jock Paget third on 27 points. There are 15 points on offer for the winner, 12 for second and 10 for third.
Nicholson has yet to check out the layout for the crosscountry, but he knows the terrain well and prefers to wait until he arrives to walk the course rather than "get too many ideas beforehand" by looking at photos or a screen shot.
He's happy with preparations of his three entries but knows some of his toughest challenges could come from other New Zealanders. Seven other Kiwi riders are lining up, including double Olympic champion Todd, who has two rides, Oloa and Ravenstar; Paget, with his top-class pair Clifton Promise and Clifton Lush; and a fourth member of NZ's bronze-medal London Olympic team, Jonelle Richards, on two well-performed horses, The Deputy and Flintstar.
"They're all looking a bit good to be honest," Nicholson, 52, laughed. "It's very exciting times, and it's great for New Zealand eventing and New Zealand sport."
Of his rides next week on the grounds of the stately home, Nicholson admits to a "soft spot" for Nereo, whom he also rode to an unlucky fourth at the Olympics.
"Avebury is a very consistent performer and quite capable of winning it again. But for me, Nereo is still a little bit better."
Certainly it would be a classic way to end a remarkable year.