As football fans living in the future, we are assailed on all sides by numbers. Pass completion percentages, successful dribble tottage, chance creation ratios, interceptions per moon phase ... if it exists, it can be measured, and compared, and used for all manner of things: to provide illumination to analysis, to pad out an opinion piece, or even to justify a frankly baffling purchase strategy.
There's no metric for terror, though. Some players are just scary. They pick up the ball, and if they're playing for you, then your eyes widen and your pulse quickens and your mouth opens and you stand up; if you're a neutral, then you let the conversation drift and refocus in anticipation; and if they're playing for them, suddenly all the private circles of your body pucker.
The two most straightforwardly scary players in the world are, obviously, Lionel Messi and Cristiano Ronaldo, both of whom send quivers a-quivering almost every time they touch the ball. However, not only are they two men apart from the rest of the game -- one has already glided his way into the pantheon, the other is rudely barging past security -- but also, neither is appearing in this Saturday's Champions League final. So let's talk about someone else. Apart from Him, and apart from Him as well, the most terrifying player on the planet is Arjen Robben.
The Dutchman is an unusual case. All the normal ingredients apply -- he's technically brilliant, imaginative, almost as quick with the ball as without, and able to kick the thing really hard if the situation demands it -- but that doesn't quite explain his scariness. His Bayern teammate Franck Ribery has all that, and is in most respects the equal of his Dutch cater-cousin, but he doesn't inspire the same fear when he picks up the ball; in other words, it's not just the football.
Nor does Robben produce with the relentlessness that might inspire fear. Brittle of both body and spirit, his career has been disrupted by twang upon strain upon niggle, and encouragingly for Chelsea, blighted with a number of significant, high-pressure misses. This season alone he's scorned both an open goal in the Champions League semi-final against Real Madrid (which ended up not mattering), and a penalty against Borussia Dortmund (which definitely did, as Neven Subotic was quick to point out). More famously, and to Howard Webb's ongoing relief, he spurned Holland's best chance to nick the 2010 World Cup final. Some players bring guaranteed punishment; not Arjen.
What makes Robben scary is the way he moves. Not the style -- though he does run with a strange, slanted, syncopated whirr, the blessed left foot obsessively tending the ball, the benighted right shambling along behind, unloved and underused, his body tidelocked as the moon -- but the lines. He has an instinctive, almost preternatural feeling for the geometry of collapsing defences: if I run here, then here, then here, this whole thing will come crumbling down around me. Like those apocryphal martial artists that just have to tap a rock to create a mound of gravel, Robben is an expert in locating, then punishing, the fissures and weaknesses in even a slightly-disorganised defensive unit. It's easy to understand why Jose Mourinho, obsessed as he is with the transition of teams from defence into attack, used him to such great effect at Chelsea.
It's not that he always scores, or that he can trick his way past a defence. It's that when he picks up the ball in broken play, the safety and security falls out of opponents' world, and even the tightest defence knows that they might end up spinning and stumbling and splayed on the floor, while Robben skips off into a gap that nobody even knew was there.