The good news for Wasps, the Premiership champions, is that only one English club, Gloucester, have ever lost a Heineken Cup semi-final - and that was against Leicester. And the bad news? The Londoners are performing far too well for comfort.
Poor teams do not win the major prize in European rugby, but out-of-form good teams frequently do. As Wasps are an in-form good team - in fact, they are an outstanding side operating at the peak of their powers - they must buck the trend in Dublin tomorrow afternoon if they are to challenge for the title against French opposition at Twickenham next month.
Think Leicester in 1997, Brive in 1998, Stade Français a year later, Munster in 2000 - these were the hottest acts of the time, and all of them caught a cold at the business end of the tournament. Those legions who find it impossible to believe that Lawrence Dallaglio and company will not go the full distance this season should remember the authority Leinster brought to the pool stages of the 2002-03 competition, and then watch a re-run of their pathetic semi-final display against Perpignan.
Tomorrow, at the same Lansdowne Road venue, Wasps take on Munster, those hardy annuals from southern Ireland who may be the best team never to have won this trophy - the Jimmy Whites of the Heineken Cup.
It could have been worse. They might have been playing them at Thomond Park in Limerick, not so much a rugby ground as a place of ritual slaughter. But this is bad enough to be going on with. Of the 48,000 ticket-holders for the most eagerly-awaited semi-final since Leicester hosted Toulouse seven years ago approximately 47,000 are likely to have Irish blood in their veins.
Appropriately, given the grandeur of the occasion, the result is too close to call. Munster hold some very big cards in the line-out, where Donncha O'Callaghan and Paul O'Connell threaten all-comers with their aggressive ball-winning, and they have a quality outside-half in the shape of Ronan O'Gara.
If their threequarter line is less than frightening, they bring a full-back of some distinction to the mix. Christian Cullen's All Black prime may be the stuff of memory, but he can still play a bit. His game-breaking powers may be central to the outcome.
Line-out frailties aside, Wasps appear to have an edge up front. Dowd, Leota, Shaw, Worsley, Dallaglio - as the old East End gangsters might have said, these are "serious faces".
Their ex-international scrum-half, Rob Howley, is playing his rugby at such a pitch that most current internationals would struggle to live with him; Alex King can shape a game every bit as intelligently as O'Gara; and in Stuart Abbott and the criminally under-rated Fraser Waters, the Londoners have the most potent centre pairing in the English Premiership.
"Yes, the line-out will play a part," conceded Dallaglio this week. "Munster are competitive in that area, certainly, but a good line-out can become a bad line-out very quickly if the opposition works out a way of playing around it."
While it is fair to say that precious few teams have neutralised O'Callaghan and O'Connell thus far, it is also reasonable to suggest that Wasps, armed as they are with all the other talents, are capable of implementing a strategy of interference. If they master Munster in this phase, they will be nine-tenths of the way to Twickenham.
Today's semi-final, the Gallic scrap between Toulouse and Biarritz at Stade Chaban-Delmas in Bordeaux, is every bit as fascinating. Toulouse, the holders, will play Frédéric Michalak, their World Cup outside-half, at scrum-half if he passes a fitness test this morning. Emile Ntamack, another player whose attacking gifts border on the unnatural, must also convince the coaching staff of his readiness to play. If he fails to do so, a third Test-class midfielder, Cédric Desbrosse, will partner the increasingly accomplished Yannick Jauzion in an all-international back division.
Poitrenaud, Clerc, Heymans, Delaigue - it is enough to scare an opposing side into submission well before kick-off. But Biarritz beat Toulouse 37-20 in a French Championship match in the Basque country three months ago, and bring some powerful artillery of their own to the shoot-out.
Serge Betsen and Thomas Lièvremont should chisel out an advantage in the back row and their scrummage is never anything but solid. Despite some injury problems in midfield - Marc Stcherbina, Guillaume Bousses and John Isaac are all injured - they have Dimitri Yachvili at scrum-half. And Yachvili, the architect of England's Six Nations defeat in Paris, is playing the best rugby of his career.