If Gordon Brown's figures fail to add up, he can always stick a penny on income tax. Any Premiership director of rugby guilty of getting his sums wrong over the next four and a half months will be lucky to escape with a sacking. The regular season still has 10 weekends left to it, but the calculators are already taking a battering. Mark Evans of Harlequins believes 37 points will keep his club among the élite; Cecil Duckworth, the Worcester chairman, reckons 32 points might be enough. At this stage, it is anyone's guess.
If Quins and Worcester were fighting among themselves, the long Premiership run-in would be intriguing enough. The fact that three other ambitious, well-financed clubs - Northampton, Leeds and Saracens - are alongside them in the mire ensures some quality entertainment between now and the middle of May.
Northampton, fresh from their extraordinary last-ditch victory at London Irish on Monday, take on Leeds at Franklin's Gardens this afternoon in the knowledge that failure there will leave them prey to all manner of insecurities.
The Saints, scrapping away like a punch-drunk Joe Frazier in the Heineken Cup but as soft as putty in the bread-and-butter tournament, must venture into some unforgiving corners of the Premiership over the coming weeks - Sale, Wasps, Gloucester, Bath - and must also negotiate the small problem of a home derby with Leicester, the form side in the country. As it is perfectly conceivable that they will take nothing from any of those matches, they cannot afford to drop points elsewhere.
Saracens, no great shakes at home but even worse on the road, have only four games left at Vicarage Road, two of them against Sale and Leicester, and must be counted among the serious strugglers.
Leeds, meanwhile, have still to welcome London Irish, Saracens and Harlequins to Headingley, and are banking on a 12-point haul from those fixtures. Anything less, and they will be up to their eyeballs in quicksand.
Much depends upon how the powers in the land - Leicester, Wasps, Sale, Gloucester and Bath - perform through the Six Nations Championship, when they are stripped to the bone on the personnel front. As Quins play Gloucester and Bath on the weekends concerned, they have an advantage of sorts. But by that time, a hundred phobias may have invaded the Londoners' collective psyche. How they could use a victory over Wasps tomorrow afternoon.
Come to think of it, there are a fair few England hopefuls who could do with a decent performance this weekend. Andy Gomarsall and Harry Ellis, fierce rivals for the red rose army's scrum-half role, face each other when Gloucester take on Leicester at Kingsholm tomorrow evening; Phil Vickery and Julian White, two world-class tight heads, square up in the same fixture, while Jonny Wilkinson of Newcastle and Charlie Hodgson of Sale also lock horns.
Andy Robinson, the England coach, will be sorely tempted to run them both when England play the first of their Six Nations games in Cardiff on 5 February. There again, he must also weigh up the recent contribution of another career outside-half, Olly Barkley of Bath, from his secondary position of inside centre.
Barkley is playing as well as any midfielder in the country, and will relish the opportunity to disrupt any cosy little arrangement Robinson might have in mind for Wilkinson and Hodgson. Not for the first time in recent months, national selection is about as transparent as a mug of bad coffee.