Saturday's RBS 6 Nations showdown between England and Wales at Twickenham will generate a number of intriguing head-to-head battles, but none more so than the coaching contest between Eddie Jones and Warren Gatland.
Here, Press Association Sport looks at how two of the biggest names in world rugby shape up going into potentially the defining game of this season's tournament.
EDDIE JONES (England)
Born: Burnie, Tasmania.
Playing career: Randwick and New South Wales.
Coaching career: Randwick, ACT Brumbies, Australia, Queensland Reds, South Africa (consultant), Saracens (consultant), Suntory Sungoliath, Japan, England.
Main trophies won: Super 12, Tri-Nations, Bledisloe Cup, Pacific Nations Cup.
England record: P3 W3.
Six Nations record: P3 W3.
First Test: Scotland 9 England 15 (Edinburgh, 2016).
Biggest win: 40-9 versus Italy (Rome, 2016).
WARREN GATLAND (Wales)
Born: Hamilton, New Zealand.
Playing career: Waikato and New Zealand.
Coaching career: Galwegians, Connacht, Ireland, Wasps, Waikato, Wales, British and Irish Lions.
Main trophies won: Six Nations, European Cup, English Premiership, Tom Richards Trophy (Lions versus Australia), Air New Zealand Cup.
Wales record: P87 W45 D2 L40.
Six Nations record: W27 D1 L10.
First Test: England 19 Wales 26 (Twickenham, 2008).
Biggest win: 81-7 versus Namibia (New Plymouth, 2011).