So what price the first Heineken Cup final between two Celtic League teams? You wouldn't bet against it. This is the first time that the Welsh and the Irish between them have supplied three of the four teams left in the competition. The Croke Park semi-final tomorrow will produce an Irish finalist and home advantage is a big thing in the Cardiff game against Leicester. But why the Celtic upsurge?

Well, Munster are simply carrying on the process of making themselves better and better. They have been the best thing in Europe for some time, they are the reigning champions, top seeds and favourites. And more than any club they will influence the way the Lions play in South Africa this summer.

Leinster have added steel. They always were remarkably talented behind the scrum and high-profile retirements haven't diminished them: the young guns have fed in at both provincial and Test level. But it's in the pack where things have changed. They are no longer a soft touch.

And Cardiff? This is the interesting one. True, there has been some new talent, but the biggest thing is that they have learned how to win games.

In Paul Tito, Ben Blair and Xavier Rush, Cardiff have the best value-for-money trio of New Zealanders ever to move north. It's not just the way they play, it's the way they think that's important in setting the tone: Rush against Toulouse in the quarter-final was just marvellous.

Then in Gethin Jenkins you probably have the best all-round prop in world rugby. He's got good hands, he's in your face and he's a battler and tackler, as likely a centre or a wing to lead a kick-chase. I never thought I'd see a more active prop than Craig Dowd but that's what Jenkins has become. Then on the wings Cardiff have Leigh Halfpenny, so good and multi‑talented that, aged 20, he is already a Lion. Tom James, a former track athlete new to rugby, is following in Halfpenny's slipstream and will soon be an international.

With the hugely influential Nicky Robinson directing the show from fly-half, Cardiff have become a side that can win by defending, as they did against Toulouse, or attacking as they did against Gloucester, who were torn to shreds by clever angles and lines of running.

But that most important of factors – knowing how to win – has made it possible for Cardiff to do both things within seven days. They have learned how to peak at the right time.

Look at the Magners League and you will see a side doing just enough; they have a good match-day 22 but are far from being the strongest squad in the land and they know it. Now look at the way in which they pick up the pace when it matters.

As the season reaches the sharp end, you see a side that has saved the best for last – or when the silverware is won. On Sunday you will probably see the side that beat Gloucester 50–12 at Twickenham, but without scrum-half Jason Spice. Much will depend on his replacement, Richie Rees. Rees is not inexperienced, but the issue on Sunday is whether he will have ever played against a guy who is so in-your-face as Leicester's Harry Ellis. If Ellis gets to Rees, then Cardiff could have trouble.

Leicester's issue also surrounds the half-backs: does Richard Cockerill play Toby Flood at fly-half or does he go with Sam Vesty? In the quarter-final a last-minute injury to Flood spared Leicester's new coach having to decide, but with Aaron Mauger also fit, Cockerill now has to grasp the nettle.

For what it's worth I'd go with Vesty who seems to be the man who has orchestrated the all-court game Leicester are now playing. I know the thinking is that he may be a yard slow, but being underestimated can be an asset and it's remarkable how often Vesty either makes a break or puts someone clear having made the half break.

But if I had to have a bet, I might put some money on the Saturday game – but only if the odds were right. Munster are rightly favourites, but Leinster showed their steel against Harlequins and have not forgotten the 30–6 drubbing they suffered when the Irish provinces last met in the semi-finals. Logic says Munster, but there's nothing more dangerous that a rugby team looking for revenge.