After the captain's picks and fiery rhetoric, the first real battle is not tomorrow's foursomes but today's opening ceremony, which marks the War of the GWAGs. The deportment, style and aura of the golfers' wives and girlfriends will set the tone for the entire competition and perhaps determine who will win it.

A team can look and feel defeated before a club is swung if their partners are struggling with the occasion or the height of their heels. So which GWAG camp will give their men the biggest boost? The Europeans are favourites, not least because Elin Nordegren, golf's very own über-WAG and wife of Tiger Woods, who is injured, will not be in the line-up. This leaves Jocelyn Hefner, Paul Casey's fiancée, to become the photographers' darling.

Only a fool would fail to take the GWAG factor seriously. Nick Faldo, the Europe captain, announced in July that he would appoint Valerie Bercher as his “lady captain”, even though they divorced two years ago; clearly he is putting the team before personal factors.

Faldo and his former wife have remained friends and Bercher, “a chic lady”, according to Faldo, helped to design the Europe GWAGs' outfits. It is widely expected in fashion circles that the Europeans will take the plaudits with their attire, which has been designed, in conjunction with Bercher, by Paul Costelloe, the Irish designer who dressed the GWAGs at the K Club two years ago.

You can tell by the way they smile and their body language as they sit together that the wives and girlfriends of the Europe team are friends. Their lunches are not exactly like scenes from Sex and the City, but they do meet to discuss GOLFAID, the charity established two years ago by players on the European Tour to help to raise money for children in need.

The Americans, by contrast, do not mix often socially, so keep a keen eye out for the fixed rather than natural smile and the flustering effect that it has on their spouses.

Faldo's pet name for his lady captain is “V”. As they peer across at their Europe counterparts, the United States GWAGs might be worrying whether that means V for Victory.

Jocelyn Hefner is the fiancée of Paul Casey

Jocelyn was raised on a farm in Florida, is a keen and successful amateur show-jumper and tops polls that seek to find the “Hottest WAGs”.

Anne Haghfelt is Soren Hansen's partner

Anne has played golf her entire life and has a handicap of 4. She is a doctor and works full time in Denmark.

Caroline Harrington is the wife of Padraig Harrington

Caroline's sister, Susie, is married to Ronan Flood, who caddies for Padraig. Caroline took a five-year course at Dublin Business School.

Montserrat Bravo Ramírez is married to Miguel Ángel Jiménez

Montserrat is among the most popular of the European wives. She and Miguel have been married for 17 years and she has taken up golf lessons.

Ebba Karlsson is the wife of Robert Karlsson

Ebba is a former make-up artist and also sang in a band, but gave that up to support Robert's career.

Katie Poulter is married to Ian Poulter

They married last September after a romance of more than ten years. Katie was a nurse when they met and is one of the few women whose outfits are frequently upstaged by those of her husband.

Kate Rose is Justin Rose's wife

She is a former international gymnast and used to be a personal assistant at IMG, which acts as Justin's agent.

Emma Stenson is married to Henrik Stenson

Emma was a highly talented junior golfer, but gave up the sport to support Henrik.

Laurae Westwood is Lee Westwood's wife

Laurae used to be a masseuse at Gleneagles and is the sister of Andrew Coltart, who plays on the European Tour, which is how she met Lee.

Lauren Smith is Oliver Wilson's partner

They met at Augusta State University, where Lauren graduated with a degree in biology. She was interim head coach of the women's golf team.

Valerie Bercher, the lady captain, and Nick Faldo

They remained friends after their divorce. They have a five-year-old daughter, Emma. Bercher is Swiss and a social science and politics graduate.

Sergio García and Graeme McDowell will be unaccompanied.

And the Americans...

Paul Azinger, the United States captain, wants to exploit home advantage to “get this crowd rocking” and his team's GWAGs have rallied to the cause.

- Amy Lepard, an aspiring singer, is Chad Campbell's wife and, despite giving birth to their first child, Dax Phillip, this month, is expected to go to the opening ceremony.

- Steve Stricker's wife, Nicki, is considered more informed than most; she has caddied.

- Amanda Leonard, Justin's wife, is considered the fittest of the GWAGs, having completed several marathons.

Nine years ago, in Brookline, Massachusetts, the wives of the US team celebrated too loudly and were heavily criticised for their “Stepford Wives” attire. But the US won then and we are expected to witness the return of “GWAG Power” at Valhalla.