Most of the remaining sides left have batsmen who can dominate but moving the ball is a rarer commodity, meaning swing bowling could prove the crucial factor in finding the winners of the World Cup.
Most other bowling variables in the game can be neutralised but not two white balls which are never any older than 25 overs.
If a bowler relies on seam, he will get minimal assistance out of flat, hard, grassless wickets designed to manufacture run-a-ball scores. If he relies on spin, few wickets in Australasia grip significantly. Ergo, if a batsman sees it early, a mishit can carry into space or, in the case of Eden Park, the stand.
It takes a slow bowler of significant guile like Daniel Vettori to provide an antidote against bigger bats, corseted boundaries and fielding restrictions which verge on breaching antitrust laws with a maximum of four fielders outside the circle.
Contrast that with a swinging ball at pace. When Trent Boult and Tim Southee deliver - Boult taking the ball into the right-hander and Southee taking it away - batsmen second-guess themselves.
There have been some prime examples at this World Cup.
Take Friday against Bangladesh. After five overs, the visitors were four without loss as they shuffled about the crease. At the end of the first powerplay, that had festered to 29-2. It took Corey Anderson dropping a second slip catch off Southee, from Mahmudullah's third ball when he was on one, to offer the clemency that fostered a quality century.
"I thought the opening overs from Trent and Tim were as good as you get," New Zealand coach Mike Hesson said. "If you try to take them on, there is risk involved. They played and missed a lot, then thought it was better to get through the new ball."
Boult and Southee have already generated marvel at this tournament.
Against England in Wellington, Southee produced the best bowling figures by a New Zealander in a one-day international with 7-33 in nine overs.
He toyed with the English batsmen. Ian Bell played inside the line, Moeen Ali and James Taylor were yorked, Jos Buttler was enticed to edge, Chris Woakes played around another outswinger and Stuart Broad and Steven Finn were caught. He was essentially unplayable.
Against Australia in Auckland, Boult delivered career-best figures of 5-27 from 10 overs. Glenn Maxwell, Mitchell Marsh, Michael Clarke, Mitchell Johnson and Mitchell Starc fell to his methodology in front of a baying Eden Park. There was always enough of a question mark to suggest his deliveries might move away from the right-handers or into the left-handers rather than his stock-in-trade.
Starc then replied in kind with 6-28 which saw Martin Guptill, Ross Taylor, Grant Elliott, Luke Ronchi, Adam Milne and Southee fall under an in-swinging yorker spell.
Other swing bowlers shape as having an effect on the playoffs.
South Africa's Dale Steyn is a master of seam and swing as the world's No 1 pace bowler, Pakistan's Wahab Riaz has the capability to deliver mayhem as he showed against South Africa, India's Umesh Yadav showed yesterday against Zimbabwe he can produce movement when pitching up, in contrast to the success his compatriots Mohit Sharma and Mohammad Shami have bowling accurately short of a length, and the unpredictability of Sri Lanka's Lasith Malinga's slinging action can still surprise.
For more coverage of the Cricket World Cup from nzherald.co.nz and NZME check out #CricketFever.