UEFA club rankings may be purely mathematical constructs (although they're probably somewhat more reliable than their cousins, the FIFA rankings), but they are pretty unequivocal here. They look at the past five seasons, and they show that Real Madrid are first and Bayern Munich are second. We're talking the likely champions in Spain against the all-but-anointed winners in Germany.

At this level, things get a little bit incestuous. Bayern boss Carlo Ancelotti -- incidentally, nobody has won the Champions League more often than he has -- guided Real Madrid to "La Decima," their 10th European Cup, three years ago. His assistant that season, Zinedine Zidane, took over at the Bernabeu 16 months back and won it again, just a few months into his top-flight managerial career.

Zidane's relationship with Ancelotti of course goes back to the 1990s, when he played for him at Juventus. Both left the club in the summer of 2001: Ancelotti amid mockery and pig noises, Zidane as the most expensive player in history. Zidane held the unofficial world transfer record for eight years, longer than anyone since World War II. The two guys who broke it (first Cristiano Ronaldo and then Gareth Bale) now play for him at Real Madrid, which at the very least means they have something to talk about.

There's more. Zidane's final tournament as a player ended, as every one knows, in infamy with a head-butt, a red card and a heartbreaking defeat in 2006. Playing in that very final alongside him was a young French winger named Franck Ribery who idolized Zidane and ended up playing for Marseille, Zidane's hometown team for which, weirdly, he never played. Ribery now plays for Bayern alongside Phillip Lahm, who probably expected to be facing Zidane in that 2006 final in Germany if not for the fact that Jurgen Klinsmann's battleship was sunk by Italy at Dortmund's Westfalen Stadium.

(That stadium, by the way, is where Mats Hummels and Robert Lewandowski, two of Bayern's biggest stars, used to play before being lured down to Bavaria, and that's perhaps the biggest difference between the two sides. Other than obvious examples like Luis Figo, it's much tougher for Real Madrid to raid their biggest rivals for talent.)

Bayern's midfield general Xabi Alonso starred for Real Madrid when they won the European Cup three years ago. Of course, he also won one for Liverpool in Istanbul when they pulled off the single greatest comeback in a European final against a Milan side coached by -- who else? -- Ancelotti.

Ancelotti and Zidane have plenty of history. So do Real and Bayern. Which one of them will prevail in the quarterfinal?

Real Madrid's midfield maestro, Toni Kroos, starred for Bayern when they won their last European Cup four years ago. (Which, incidentally, was at Wembley, against a Borussia Dortmund team featuring Lewandowski and Hummels.) Arjen Robben also played for Real Madrid, although he was effectively shown the door when they signed that Ronaldo guy back in 2009.

Folks, these aren't your one-percenters, these are your 0.1 percenters, which incidentally may explain the rampant levels of cross-pollination: people like that tend to move in the same circles. They've both been in the top five of Deloitte's ranking of the world's richest clubs for the past decade and they ain't going anywhere anytime soon.

Real and Bayern rank first and third for both European cup wins and final appearances. They've won a combined 58 domestic championships. They come from the two countries who won the past two World Cups. They are the uber-elites and they revel in being different (Bayern's motto "Mia san mia" roughly translates to "We are who we are") and blue-blooded (there's that crown on top of the Real Madrid crest and the "Hala Madrid," or "Hail Madrid," anthem).

Supporters of rival (they might say lesser?) clubs hate their hegemony and entitlement, but truth be told, they don't care, chalking it up to little more than envy and the price you pay for being No. 1. And they may well be right.

The two teams have faced each other 10 times in knockout competition, and the count is deliciously deadlocked. Both teams have advanced on five occasions and each team's home record (eight wins, one draw, one defeat) is a mirror image of the other.

Of course, the last time they faced each other is also the one that looms largest. Three years ago this month, Pep Guardiola's Bayern were pummeled by Real Madrid in the Champions' League finals, 5-0 on aggregate, including a 4-0 road grading at the Allianz Arena. Sitting on the Madrid bench that night was Ancelotti (if you can't beat them, join them -- or in this case, get them to join you). Alongside him, taking it all in, was Zidane.

On Wednesday, the Jedi meets his former Padawan. The only certainty is that at least one uber-aristocrat from the Champions League era won't make the final four.