"Having a hand illegally on the ball, long enough for the referee to say: 'Hands off'. Long enough to slow attack down.
"There's no McCaw this time but there are three opensides, all breakdown experts. The tournament will be won by the team that controls the tempo of the game — and the breakdown is the heartbeat of ball in play — but also the area of contentious calls that will be made by officials aware of what their masters want.
"A clean and fair competition. 'Clean out' at your peril. The more jackal options, the more chance of your team winning the battle of the whistle.
"New Zealand, the most positive attacking team in the world, have their flip side. They are also the most cynical cheats at a breakdown."
Barnes predicted an army of opensides and other breakdown exponents would dominate the tournament, which starts in Japan later this month.
England had flankers Tom Curry and Sam Underhill, backed up by lock Maro Itoje and No. 8 Billy Vunipola. He predicted Wales might pair Josh Navidi with Justin Tipuric. The Wallabies had the Michael Hooper/David Pocock combo to rely on.
"Defenders who create nothing but a trickle of slow possession damn the game and gain an edge," Barnes claimed.
"New Zealand, beautiful and ugly in equal measure, are well aware of the fact.
"McCaw's greatness was as much to do with his negativity at breakdowns as his inspiring commitment as captain.
"There is no McCaw now, but there remains a ruthless army of openside mercenaries ready to kill quick ball.
"When the price isn't so painful, when the referees are protecting legions of these assassins of the fine arts, who can blame coaches for picking them in ever greater numbers?"
