The art of tactics is not defined by winning but by percentages. If a team has a 30 per cent chance of winning a game but their manager is able to transform that into a 40 per cent chance, he has done his job, irrespective of whether his side actually does win.
Barcelona dominated their Champions League semi-final first leg against Chelsea on Wednesday, having 23 chances to the home side's five, hitting the woodwork twice and missing two sitters, but Roberto Di Matteo must take credit for setting his side up in a way that disrupted their flow and prevented Barcelona having more opportunities.
Chelsea also completed a quest that has frustrated countless teams over the past few years: they found space behind Dani Alves. Logically, everybody knew that it had to be there. It was there when he played for Brazil and went rampaging down the flank, but mystifyingly disappeared when he donned a Barcelona shirt, no matter how high up the pitch he played.
The reason is threefold: firstly, Gerard Pique is superb at covering for him; secondly, Dani Alves is lightning fast and can take advantage of the slightest hesitation to get back to cover; and thirdly, Barcelona's pressing is so intense that teams find it hard to measure passes into space.
On Wednesday, though, there was no Pique, and Carles Puyol perhaps offers less reliable cover. The last two of those three factors, meanwhile, were nullified by the pace of the break, as Frank Lampard dispossessed Lionel Messi on halfway and clipped a perfect ball into the path of the charging Ramires. The Brazilian, who has been one of the unsung stars of this season, accelerated into space with Dani Alves yards behind him and crossed for Didier Drogba, in one of his rare standing moments, to score.
Ramires was excellent again, all but nullifying Danni Alves as an attacking threat in collaboration with Ashley Cole, who might have had his best game since Euro 2004 when he was superb in stifling Cristiano Ronaldo in England's quarter-final against Portugal. The pair got the balance right, defending when they needed to, but always being prepared to break so that Dani Alves couldn't, as he often does, simply play as a midfielder.
That aside, this was a victory for the simple virtue of shape. Chelsea maintained a deep back four, with a five-man string in front of it. Juan Mata - used, unusually, on the right as Ramires switched flanks to counter Dani Alves - did play slightly higher, perhaps to try to pin Adriano back, but he was a lonely figure stuck out on the touchline.
The key was the space between the lines: it wasn't quite the 25m from centre-forward to centre-back that Arrigo Sacchi demanded from his AC Milan team, but there was rarely more than 10-15 yards between the defence and midfield.
That meant Barcelona spent a lot of time passing around in front of Chelsea's midfield, waiting for spaces to open up, which they rarely did. Messi, for instance, is at his most dangerous when he is able to dart into what the former Borussia Dortmund and Bayern Munich coach Ottmar Hitzfeld calls "the red zone" - that is, the central area just outside the penalty area.
Sure enough, when he did get into that pocket he was dangerous: as when dinking a pass over the top for Alexis Sanchez to lob onto the bar after nine minutes, or when, eight minutes later, he set up Andres Iniesta for the shot that produced the Petr Cech save that brought about the Cesc Fabregas miskick in front of a yawning net. Or when, after 43 minutes, his characteristic surge and through ball played in Fabregas, whose flick over Cech was cleared off the line by Cole.
In part, that is down to the discipline of the team as a whole, but it also says much for Mikel John Obi, who gave a splendidly focused performance, belying his reputation for occasional wildness.
And yet, it could so easily have gone the other way. Had Sanchez's lob come down four inches earlier, had Pedro's late low sidefoot slithered two inches to the left, had Sergio Busquets not boomed the rebound wide, had Fabregas not miskicked that simple chance, had Sanchez not shoved just wide from six yards after being found by a looped Fabregas pass, had Cech not made a fine sprawling save to keep out a deft Puyol header... this isn't one or two near misses, it's half a dozen - more that is, than Chelsea had chances in the game.
Does that mean Chelsea were lucky? To an extent, yes. But the key from their point of view is that they minimised the amount of luck they needed. Play that game again ten times and Barcelona would probably win more than half, but the point is that they wouldn't win eight or nine, which is what you'd have estimated their ratio to be a couple of months ago. If Chelsea are to prevail in the second leg, they will need similar discipline and probably just as much luck, but there are a couple of details in their favour.
For one thing, Barcelona don't have an away goal which means that if Chelsea could nick one, Barca would have to score three. They're perfectly capable of doing that, but it gives Chelsea some breathing space. And Barca do look vulnerable.
The most basic long ball caused them problems and Gary Cahill, another who had an excellent night, was almost presented with a simple chance from a long throw-in early on. More than that, they looked tired and flat as a result - as Real Madrid had against Bayern Munich the previous night. Worryingly for them, there'd been similar signs of fatigue against Levante at the weekend as they resorted - strangely for them - to a string of crosses.
Barcelona were still the better team on Wednesday. They made around four times as many chances as Chelsea: those are figures that should bring victory. But Chelsea brought them down to a level of mortality - just as England had done against Spain in November - that gave them a puncher's chance. They took it, but to take it again in the Camp Nou next week will be an even greater challenge.