Australia's best chance of finally stopping Kane Williamson could rest with the newest member of their Test squad: Steve O'Keefe.
Even though David Warner leads the Trans-Tasman Trophy run tally, New Zealand's Williamson has arguably been the most formidable batsmen of the series in compiling 397 runs at an average of 132.33.
Williamson made commanding centuries in the first innings in both Brisbane and Perth. It took a borderline leg-before decision to remove him in the second innings at the Gabba, for 59, while at the WACA Ground he was unbeaten on 32 when match ended in a draw.
The right-hander's ease has been reflected in Australia's bowlers managing only 11 maiden overs against him among the 560 deliveries he faced: four from Mitch Starc, three from Josh Hazlewood and Mitch Marsh and one from Nathan Lyon.
Williamson's form has led to Peter Siddle saying he would try to "bore" Williamson out at Adelaide Oval, by starving him of scoring opportunities.
Black Caps coach Mike Hesson was unperturbed.
"Kane will just do the same thing he does normally, which is watch the ball and see what happens," Hesson said.
"Many sides have tried different things against Kane, some have been more successful than others... he'll just go about his work as normal.
"He's playing well. He's a really unflustered sort of character. He never gets too far ahead of himself so you wouldn't know if he got a hundred in his last game or missed out, he just goes about his work."
O'Keefe's fine record with the pink ball at Adelaide Oval — he has taken 18 wickets at 18.22 in three day-night matches — was a key factor in his selection.
While the pitch conditions may count against his playing, the Australian selectors could change their mind if they decide their plans to shackle Williamson are futile.
In the five years since Williamson has debuted, a third of his dismissals have been against left-arm finger-spinners, a conspicuously high percentage given how many of those bowlers he has played against compared to pacemen and other types of spinners.
India's Pragyan Ojha has dismissed Williamson five times in five Tests, while Pakistan's Zulfiqar Babar and the West Indies' Sulieman Benn have each twice claimed his wicket. Sri Lanka's Rangana Herath, one of the other left-armers to dismiss Williamson, is of a similar stature to the diminutive O'Keefe.
Since Australia named their squad for Adelaide last week coach Darren Lehmann has been adamant that O'Keefe is in contention to play.
If O'Keefe was selected, it would be the first time since January 2006 that Australia have fielded two specialist spinners in a home Test. Off-spinner Nathan Lyon, who bowled in tandem with O'Keefe for a total of 27 overs over in last month's day-night shield match at Adelaide Oval, welcomed that prospect.
"We play all formats together — for the [Sydney] Sixers, NSW — so we bowl well together, we work off each other really well and we support each other really well," Lyon said. "I'm all for it. If they're going to play two spinners I think Steve O'Keefe is the right man."
Even if Australia decide to persist with three specialist pacemen and exclude O'Keefe, they could be tempted to test Williamson against left-arm spin by trying part-timer Adam Voges.
Voges has bowled only three overs across his nine Tests: two on his debut in the West Indies, in Dominica, and one at the Gabba. Williamson scored two singles in the three deliveries he faced from him in the latter.
