Steve Waugh has warned England they are set to be exposed by Australia in the Ashes if they don't have a back-up plan for when all-out attack doesn't come off.
England's 'Bazball' revolution in the past 12 months has revived Test cricket in the country, and prompted the most anticipated Ashes series in 17 years.
But Australia have made no secret of the fact they have serious question marks over whether it can withstand the Australian attack.
England have scored at 4.85 an over in the past year while racking up an 11-2 record in Test cricket, and five of their batsmen have scored at a strike-rate of above 75.
In contrast, Australia have made their game out of building pressure and strangling opponents with the tightest economy rate of any team in recent years.
Steve Smith cast doubt on England's approach on Thursday, when he questioned for a second time how it would work against Australia's attack.
Waugh is convinced it won't always come off, and said England were at serious risk of collapsing to their first Ashes series loss at home since 2001 if they didn't have back-up plans.
"That is the big question mark over so-called Bazball. What is Plan B? Have they got a Plan B?" Australia's former Test captain asked.
"If they haven't then they are going to be found out.
"They have shown they are good enough to carry this style of cricket off but the ultimate test will be against a world-class bowling attack, which Australia has got.
"It is exciting but to me the jury is out at the moment. Does (Bazball) hold up under scrutiny against a really good bowling attack in maybe challenging conditions?"
Regardless, Waugh said he did not expect England to go away from the fearless approach.
"There is no doubt it won't work all the time but I think with (coach Brendon) McCullum and (captain Ben) Stokes they will have the courage to go through with it," Waugh said.
"They can't chop and change. Have they got a back-up plan? I'm not sure. That might find them out."
Waugh's successor as Test captain, Ricky Ponting, said it was not impossible for England to pull off the ploy, but is adamant Australia can find answers to silence the hosts.
"I’ve got a few thoughts on what I'd be doing if I was an Australian fast bowler," Ponting said.
"I think the reason the way England have played for the last couple of years is with this series in mind.
"They’ve been trying to find a brand of cricket that they can play that’s going to win an Ashes series."
