There's always a danger in reading too much into just one round of the Heineken European Cup, especially the opening weekend. But three truisms or trends emerged.

One, that it, eh, rains an awful lot more in this part of the world than France (quelle surprise); two, that, um, French and Welsh teams don't travel too well (not likely to register on the Richter scale of surprises either); and three, perhaps most pertinently of all, the Celtic League teams hit the ground less quickly than their English or French counterparts.

As last season's results indicated, despite prevailing opinions to the contrary, the Celtic League is not innately inferior to the English Premiership or the French Championship, given the 20 pool match-ups between Celtic and English teams yielded 10 wins apiece. It's just the opening stages of the Celtic League hadn't prepared their entrants for European rugby as intensely as the English and French domestic leagues had done. It's true the three Irish teams in the European Cup all won, while the English had five wins out of seven and the French four out of six, whereas the quartet of Welsh sides and both the Scottish and Italian pairs lost all their games.

While not denigrating what was a pretty satisfactory opening weekend for the Irish provinces, closer examination shows they beat perhaps the poorest Welsh side at home, the bottom-placed English side, also at home, and an Italian side.

More tellingly, in the six clashes involving Celtic League sides against English or French teams, there was just one win - Munster against NEC Harlequins at fortress Thomond - and five defeats. Not only did Harlequins - on a run of seven domestic defeats - come within a score of ending Munster's 17-match winning run at Thomond in the cup, but two other sides on their downers ended losing runs away to Celtic League teams.

Northampton, after a run of five successive league defeats, won 13-9 in Glasgow, and Newcastle, following three heavy defeats in a row domestically, won 10-6 against a Gwent Dragons team who themselves had won five Celtic League matches on the bounce. Even losing in the Zurich Premiership seems to have been better preparation for the European Cup this season than winning in the Celtic League.

This impression had been hard to ignore for the previous month and a half.

Celtic League matches just didn't look as if they were being played with the same intensity. Without wishing to regurgitate that hoary old chestnut about the Irish players' 10-week pre-season, it clearly has had something to do with it. Not alone have Leinster and Munster - with only four preparatory games at full strength - been late off the blocks, but the ripple effects have been felt throughout the Celtic League. Even the hitherto unbeaten Ospreys and the high-flying Dragons were perhaps given false delusions of grandeur.

Despite playing seven league matches compared to 10 in France, the English clubs collectively look in better nick just now, and again this was to be anticipated. With Worcester's promotion at the expense of Rotherham, the old cliché there are no easy games in the English top flight has been given added validity. In France, where away wins are virtually against the rules, and the first division has four more teams, the same cannot be said to the same extent.

The evidence of the opening Challenge Cup matches supports this theory, given all five English sides emerged unbeaten, despite three of them having to travel to France. None of the three French sides away from home in the European Cup managed to cross the whitewash. Biarritz seemingly hadn't the slightest inclination to do so at Wasps and even Toulouse must have used up much of their supplies of holy water from Lourdes in Stradey Park on Friday night.

It's not just the stats though. The Irish provinces all showed character in digging out wins but even Munster weren't in their customary European Cup mode, and nothing about the highlights and reports of their win in Treviso refute the undeniable impression that, likewise, Leinster's best performances this season are still in front of them.

This has particular concern with regard to Bath's visit to Lansdowne Road next Saturday. John Connolly's team appeared to win more handily than the scoreline suggests (22-12) at home to Bourgoin and a cursory glance at the team's recent fixture lists readily explains they are at a better pitch right now, eight matches together culminating in games against Gloucester, Leicester, Wasps and Bourgoin, whereas Leinster's four outings at full tilt have been against the Dragons (beaten well), Edinburgh, the Ospreys (beaten well) and Treviso.

"You have to win your home games in the European Cup," was the mantra of the opening weekend. In fact, Wasps didn't adhere to this last season, but only because they reversed their home defeat to the Celtic Warriors a week later. Besides, that was the exception rather than the rule.

As a minimum of five wins out of six is normally a prerequisite to winning a pool, or at any rate obtaining a home quarter-final, and the trip to Castres six days after the autumn internationals looks even more daunting than The Gnoll, Munster are also facing something of a must-win trek to Neath against the Ospreys this Sunday.

The pressure isn't quite so acute on Ulster against Gloucester at Kingsholm, where the home side have never lost in the cup and few outside the squad can realistically expect them to win, but these are simply massive games for Munster and Leinster. And for their sakes, you'd like it if they were flowing just a little more freely.

It might be stretching things to suggest these weekend's games will make or break Munster's and Leinster's Cup ambitions. But then again, it mightn't be. The hope must be that last weekend's opening matches will have sharpened them up, and will serve to bring them closer to European mode.

They better have.