Benetton-Ford offer the most immediate challenge to Williams, and Michael Schumacher may well prove an albatross to Ayrton Senna. Mile-high confidence and commitment equals speed and the new Ford Zetec R engine is already faster than last year's six GP-winning unit. The unfortunate JJ Lehto is still unfit to take part in Brazil and 'cub driver' Jos Verstappen will deputise. But Interlagos will prove a daunting venue for his debut.