The word "mercurial" could have been invented to describe the French international rugby union team, always changing, always evolving, and not always for the better.

On their day Les Bleus can beat any team on the planet as they proved conclusively when they destroyed the near-invincible New Zealand All Blacks in the 1999 Rugby World Cup semi-final.

Naturally, in true French fashion, they then failed to ignite against Australia in the final at Cardiff's Millennium Stadium and were soundly beaten by the Wallabies.

At the 2007 Rugby World Cup they again stunned the All Blacks, this time at the quarter-final stage, but were then sunk by England at the very next hurdle.

Les Bleus' collective Achilles heel was again exposed in the 2009 Six Nations Championship as, having started as slight pre-match favourites, they imploded against England, looking anything but the world beaters they can be when everything clicks into gear.

Current coach Marc Lievremont has come in for a lot of flak for failing to inspire a consistent winning mentality into his troops, but previous incumbents have suffered the same problem - namely which French team will turn up on a given day. No doubt his guess is as good as ours.

For the only thing predictable about Les Bleus is their very unpredictability. That is what makes watching them such an enticing prospect.

Despite that, Lievremont has a great crop of young talent at his disposal and in any major tournament - be it the Six Nations or the Rugby World Cup - they can never be written off.