Football too often denies us the truly epic tie, the meeting of the two great sides of the age, and it's perhaps that more than anything else that makes Tuesday night's Champions League semi-final between Bayern Munich and Barcelona so enticing.

This has the sense of an era-defining encounter: Barcelona, who have dominated Europe for the past half-decade (it's a remarkable fact that, even in their sixth successive semi-final, it still feels as though they have not quite achieved what they might have done in the Champions League) and Bayern, who could be the dominant force of the years to come: Pep past against Pep future in a Pep-less present that could mark the transition from one generation to the next. Or could, conceivably, were Barcelona to win convincingly, assert Barça's hegemony and perhaps even the growth of a new dynasty under Tito Vilanova.

Yet amid the talk of historical sweeps – justified to an extent by the fact that Barça and Bayern are this season's champions – there is the awareness that the champions of last year in either Spain or Germany will await in the final. Neither Real Madrid nor Borussia Dortmund – one about to change their manager, the other lacking the financial muscle – look likely to embark on a dynasty, but either is a realistic and would-be worthy champion.

As Miguel Delaney has pointed out, games in which a power just past its peak meets a new power on the rise have been remarkably infrequent – in part because Barça are the first side to command their era since the Juventus of the mid-90s (although the changing format and increased competition meant neither side reeled off hat-tricks of titles like the great sides of the past and their domination was reflected as much in their reputation and influence as in trophies). He suggests there have only been three previous examples, of which the most relevant seems the game between Ajax and Bayern Munich in 1972-73, a tie won 5-2 on aggregate by Ajax after a crushing 4-0 victory in the first leg in Amsterdam.

Ajax, on their way to a third successive European Cup, were probably just past their peak, internal divisions beginning to emerge after the iron grip of Rinus Michels had been released. Bayern then perhaps weren't such a mature side as Bayern now, but West German football was unquestionably on the rise, as had been shown by the national side's breath-taking success in the European Championship in 1972. Then, as now, the clash was between slightly differing variants of Total Football. There was the Dutch school, all hard-pressing, high offside line and interchanging of positions, and the German school, which didn't push up to play offside and, which, while still essentially about the creation of space through intermovement, was perhaps slightly more rooted in physicality.

And that's where the strands begin to intertwine. The Dutch school was transplanted, first by Michels and then by Johan Cruyff, to Barcelona. The German school was practised as much by Borussia Mönchengladbach as by Bayern, and it was there that Jupp Heynckes, the present Bayern coach, learned the game. The tactical make-up of both the modern Bayern and the modern Barça was established by Louis van Gaal, whose first experience as a coach had been at Ajax.

Pep Guardiola credits Van Gaal even more than Cruyff as the man who influenced his thinking on how the game should be played and at Bayern he will, as he did at Barça (via Raddy Antic's brief caretaker stint) inherit a side from somebody who succeeded Van Gaal. So the basic styles of the two teams are similar, something borne out by the statistics. Across Europe's top five leagues this season nobody has achieved a higher percentage of possession than Barcelona with 69.6%; Bayern lie second in the table with 63.6%. Barcelona have a higher pass completion rate than anybody else (89.7%); Bayern are second (87.4%).

But for all the similarities, there are subtle differences. Most obviously, there is the shape. While Barcelona play a 4-3-3 with Lionel Messi operating as a false nine (he could, conceivably, operate behind David Villa as a more orthodox centre-forward, with the right flank vacant but for the surges of Dani Alves, as he did against Milan, but it seems improbable on Tuesday night), Bayern prefer a 4–2–3–1, a difference that plays out in the centre of midfield, where Bayern will have two holding players and one advanced central midfielder and Barça one holder flanked by two more creative players.

That effectively means the shapes will match up, Sergio Busquets picking up Thomas Müller with Xavi and Andrés Iniesta facing Bastian Schweinsteiger and either Luis Gustavo or Javi Martínez. In itself, that's unlikely to favour one side or the other: three central midfielders all doing the jobs they naturally do, although Xavi must be wary of Schweinsteiger's forward surges.

What could complicate things for Bayern is Messi dropping deep. Does one of the centre-backs follow him, potentially creating a gap for a wide player – Villa and Pedro, presumably – to dart inside? That is a particular danger given how attacking both Philipp Lahm and David Alaba are; an advanced position would make it all the harder to shuffle in and form a de facto back three. But if the centre-backs stay where they are, Messi creates a three on two in Barça's favour at the back of the Bayern midfield. Which is, of course, why for a team as good in possession as Barça and not looking for a long outlet ball from the back, a false nine is such a dangerous proposition.

That's where Barça may have an advantage. Where Bayern have a clear edge is in set-plays. No side in any of the top five leagues in Europe wins as few aerial duels per game as Barcelona (9.7 – Wigan are second with 10.4). In part that's because they control the ball sufficiently that opponents have limited opportunities to launch high passes at them, but it's also because of a natural disinclination based on being short. Bayern are 30th in that list, winning 14.9 aerial duels per game. It's a problem exacerbated by the absence of Carles Puyol and, with Adriano suspended, Marc Bartra, who has made only 21 appearances for Barcelona in total, is likely to play. Bayern are a bigger team and must think corners and free-kicks offer a great opportunity.

It's important, though, not to be drawn into the cliche of physical Germans against technical Spaniards, even if Bayern do have a slight physical edge. What will be fascinating is seeing not only the two best possession teams in Europe facing off, but also the two best pressing sides. Barcelona's players will never have been placed under such co-ordinated pressure on the ball as they are likely to be on Tuesday – and vice-versa. It's in the pressing as much as in his goals that Mario Mandzukic, suspended for the first leg, will be missed. "His stamina is endless," said Felix Magath. "I think he could play two back-to-back high-tempo games." Much as Samuel Eto'o used to do for Barça, Mandzukic leads the press for Bayern; whether Mario Gomez has the energy – or indeed the intelligence – to do that is doubtful.

But these are the details. They may determine how the tie plays out but what will be remembered is the outcome, whether the age of Barça has yet become the age of Bayern.