"If you're too wired up mentally, you could collapse, especially in today's media and spectator cauldron. The helmet used to be my zone. I called it my space helmet. Bowlers could stare you down and sledge and, if you engaged, it generally meant they were getting under your skin. I tried to offer a minimum of body language in response.
"The key thing is to switch on and off. I liken it to extending your battery life. You become mentally exhausted if you concentrate 100 per cent of the time. You need a fierce focus when the bowler is running in, then you let the engine idle. Guys that get out for 30 are often mentally but not physically exhausted. It's a case of unwinding the brain between balls."
Edgar says the Australian attack can pose problems but they are not an invincible force.
"One advantage today is players have all sorts of analytical data at their disposal; that intelligence includes the lines they bowl and the fields they set. There are few surprises.
"The only thing that might upset the New Zealand preparation is [Shane] Watson, Johnson, Harris and Cummins being ruled out. It means someone who they haven't faced much, like Mitchell Starc or James Pattinson, comes in from the Australia A match.
"They can't over-complicate things. These guys will still bowl bad balls and our batsmen are obliged to hit them to keep the pressure on."
Gary Hermansson is author of the recent book Going Mental Through Sport: Excelling Through Mind Management and was sports psychologist for the New Zealand team from 2005-07. His tenure included 14 tours during coach John Bracewell's reign.
Hermansson came with a sporting pedigree, having played cricket at New Zealand Universities and under-23 level as well as rugby for Manawatu and Wellington.
His advice centred around uncluttering the mind.
"Sometimes a fear of consequences kicks in. When you think of the potential danger facing fast bowling, you risk tightening up mentally and physically. That affects your decision-making and co-ordination.
"The more you stay in the moment using your intuition, the more likely you'll see a ball clearly to do something with it. Obviously there's a level of skill involved but the players have to trust their preparation."
Hermansson says facing tennis balls at 160km/h is fine as a physical preparation technique but facing fast bowling requires mental strategy too.
"If you're reiterating the idea of watching the ball, you're more likely to produce a quick reaction. The danger is when you lose that focus and protect yourself by becoming frightened and scared. If that encroaches on your batting, you become preoccupied with what might happen rather than what will happen.
"Standing around the dressing room can also mean players become preoccupied geeing themselves up. I'd advise them to keep their breathing loose and relaxed and smile when they cross the boundary rope.
"That might sound a bit weird but if you force a smile, you tend to increase your energy and enjoyment. It's about developing techniques to soak up your time like taking mini-breaks with a bit of gentle meditation when you're next man in; anything that keeps you alert and relaxed simultaneously."
Hermansson accepts that won't work for everyone but says it's about players finding an edge at the highest level.
"Batsmen spend hours in the nets getting the feel right with bat on ball but time should also be spent on deliberate or systematic ways to deal with the mental side of things. You can't necessarily rely on old habits to carry you."
