Stability, balance, alignment – the holy trinity of athletic performance.

Everyone from golfers to gymnasts to tennis players and boxers train and practise to hone those fundamentals. They are the foundation stones of power, control and consistency. Two out of three ain’t bad and can get a job of sorts done, but for consistency you want the triumvirate.

Mitchell Starc has spent much of his glittering career fighting the demons for perfection, but recently he has found that sweet spot.

He has graduated from a bowler who might hit second slip, then fine leg, then uproot middle stump to one who mixes outrageous inswinging yorkers with clever angled seamers that constantly challenge batsmen.

Speed is important: anything above 140km/h hastens shot-making, shortens decision time and forces batsmen to follow the angle while guarding against the inswing. The left-handed bowler’s advantage to righties is clear, but then he forces left-handers to play at the swing while protecting their toes.

Witness day one of the Gabba Test and Ben Duckett’s edge to slip while covering up in dogged defence. Ditto Ben Stokes in Perth, where he was defending with cautious footwork and the softest of hands but couldn’t resist the irresistible.

Without Mitchell Starc Australia would be in deep trouble in this Ashes series.Credit: Getty Images

The tall torso and long arms which help generate the threatening pace also make an athlete prone to errors. Threatening both cack- and non-cack-handers neutralises the change in line that mixed opening combinations create. The Duckett wicket made it 26 times Starc has struck in........

© The Sydney Morning Herald