Rugby World Cup:Brian Ashton is a keen student of history so he may be aware of Walter Scott's cautionary words: "Oh what a tangled web we weave when first we practise to deceive."

The England coach appears to be indulging in mind games ahead of tonight's crucial Pool A clash in Paris; yesterday he announced Mike Catt and not Andy Farrell would wear the number 10 jersey.

England have been in a state of flux in preparation for this match - primarily the injuries to Jonny Wilkinson and Olly Barkley - and Farrell was originally named in the outhalf position and answered questions accordingly about his new role.

Yesterday, though, Ashton asserted his team selection had been misconstrued, cryptically offering, "They (Farrell and Catt) will both be playing as inside backs and that's all I will say."

The currency of his response lacked the watermark of authenticity, so the media decided to crunch some numbers.

Ashton, sensing he would have to be a little more forthcoming, at least numerically, finally sighed, "I said they would be both playing as inside backs. It doesn't matter, does it? Alright, Catt at 10, Farrell at 12."

So there you have it, or do you? England will be adopting a multi-layered approach to the pivotal outhalf role, players, one suspects, forming an orderly queue to be first receiver.

Theoretically it has an appeal, the most obvious being the left-footed (Farrell) and right-footed (Catt) option, but in practical terms it is a tactic unlikely to faze the South Africans.

Ashton has hardly been transparent this week, and another inquisitor mischievously asked him if Wilkinson might suddenly materialise in the Stade de France tonight. Apparently he won't, but he as well as Barkley could be available for England's next match, against Samoa.

If the media were a little skittish about Ashton's intentions, Catt - the man who will wear 10 on his England jersey tonight - purred: "I think Fez (Farrell) and I are going to chop and change (between outhalf and inside centre). As long as we're clear on what we're doing and understand what we're trying to do, Fez and I are just going to try and control the game. We are the main decision makers and it's down to us to put ourselves in the right parts of the pitch."

They've probably run out of chalk and blackboard space at the team hotel but tonight won't be rugby's version of differential calculus. It's a simple equation involving the English pack achieving parity or better to stand any chance of beating a Springbok side that enter this match as strong favourites.

The absence of Phil Vickery - suspended for two games - will be significant. Matt Stevens is an excellent footballer, mobile, strong and with good hands, but Bath's South African-born tighthead prop lacks that mean streak. In tonight's clash of the packs that's a quality that will be invaluable.

Martin Corry, a player who leads more by deed than by word, takes over the captaincy, while Nick Easter's athleticism is preferred to Lawrence Dallaglio's experience at number eight.

England lost five lineouts against the USA, and at the Stade de France they meet the world's best unit out of touch (though Ireland might dispute that assertion).

Ben Kay is going to have to exercise shrewd judgment, while hooker Mark Regan might be allowed less time and energy for the trash talking than usual.

The Springboks possess a superb Victor Matfield-inspired lineout and a punishing scrum, and their tight five can all carry ball.

Schalk Burger - whose ban was reduced from four matches to two on appeal yesterday morning - will obviously be missed, both in defence and in rampaging attack, but coach Jake White has publicly praised his deputy, Wikus van Heerden.

The loss to injury of Jean de Villiers in midfield is a setback but his deputy, 20-year-old Francois Steyn, is prodigiously gifted.

The skills work conducted by the Australian Eddie Jones with the South Africans was manifest in the quality back play in their opening game against Samoa, the premise being to release Bryan Habana into space and watch the fleetfooted winger embarrass defenders.

England are certainly more pedestrian in midfield, where Jamie Noon is a gutsy ball carrier but is prone to poor decisions when in possession.

Leicester's Dan Hipkiss is a better player going forward but mediocrity seems to hold sway in the English midfield.

Paul Sackey, strong and very quick, provides a cutting edge on the wing, with Jason Robinson switching to fullback.

The defending world champions will be hoping he can find some space to use those twinkling feet.

It's difficult to see beyond a Springbok victory. They're in better form, should have an edge in the set pieces, have a more solid halfback pairing, have more creativity in midfield and have the advantage in place-kicking, in the person of the prolific and vastly experienced Percy Montgomery. Farrell was an accomplished place kicker in rugby league but has not had to take that responsibility since switching to union.

Pride and unity engendered by the awareness that few give them a chance in Paris should ensure England will be committed and competitive.

That, however, is unlikely to suffice unless the Springboks allow themselves to be dragged into a slugfest.