Cricket: Four key contests of the Ashes

Australia and England are set to take part in the prestigious Ashes series starting this week. Photo / Getty

* Mitchell Johnson v Adam Lyth and Alastair Cook

Jonathan Trott was slated to open throughout this series but his retirement opened the door for Lyth. The 27-year-old made a century in his second Test, while Cook also scored runs against New Zealand. Can they see of the new ball or will Johnson wreak more havoc?

* Ben Stokes v Shane Watson or Mitch Marsh

The value of a game-breaking allrounder that can turn a Test with either bat or ball was well highlighted by Andrew Flintoff's heroics in the 2005 series. The combative Stokes will draw confidence from the fact his maiden Test ton came in Perth, while Watson and Marsh are locked in a selection battle.

* Nathan Lyon v Potentially Seven Left-Handers

Lyon has already stated he can't wait to attack the hosts' mollydookers. The offspinner has improved significantly since the 2013 series and looms as a point of difference. The hosts are expected to back allrounder Moeen Ali to perform their spin duties instead of employing a frontline tweaker.

* Steve Smith v Stuart Broad and Jimmy Anderson

Ranked the best Test batsman in the world, Smith was always going to be a talking point in the lead-up. Broad opted to get on the front foot, declaring the 26-year-old's promotion to first drop will help England. Can the hosts' swing kings dismiss Smith cheaply to back up Broad's assertion?

-AAP