Sometimes in football a few small events make a big difference. Everything can be going very well indeed, then one small mistake leads to a couple of big ones and suddenly a decent performance looks like a dreadful one. Inevitably, the aftermath sees all positive aspects swept under the rug and the negatives are highlighted, exaggerated and used as ammunition against whoever the scapegoats are.

Few games will stand as better examples of this than Saturday’s Clásico. Read almost any newspaper or internet column and you’ll be told that: Barcelona should really have lost 10-0 to Real Madrid; Lionel Messi was invisible; Andrés Iniesta is finished; Luis Enrique is out of his depth, and so on. It’s all exaggerated nonsense.

Of course Barça deserved to lose. They made basic strategic and technical mistakes that would embarrass most amateur footballers and gave themselves a mountain to climb. Having to chase the game, they overcommitted and left themselves open to the counter, allowing Madrid to create even more chances. Had they not repeatedly messed up the final pass, Cristiano Ronaldo, Karim Benzema and company could have achieved a manita. That wasn’t a real reflection of the contest, however.

The first half was probably Barça’s on balance. Luis Enrique’s narrow 4-3-1-2 system and his surprising selection of Xavi Hernández worked well, allowing Barça to dominate the centre of the pitch and have a majority of ball possession. Sergio Busquets was regularly free to keep the ball moving quickly and he slipped Messi several incisive vertical passes, allowing Messi to turn and drive at Madrid’s defence and combine with Suárez and Neymar, who were moving out to the flanks to play 1v1 against Marcelo and Dani Carvajal.

Real Madrid looked vulnerable. Their 4-4-1-1 seemed too reactive, drawing too many attacking players into primarily defensive roles, a problem that has been their Achilles’ heel for years. As expected, they quickly assembled in two banks of four, waited for Barça’s moves to break down and then counter with quick vertical bursts past players who simply couldn’t match their physical capabilities.

Though they played as the reactive side, Carlo Ancelotti was far from doing a Mourinho. Madrid did not park the bus for the entire match. Luka Modrić, Toni Kroos, James Rodríguez and Isco are all excellent footballers at or approaching their peak and their quick, accurate passing and positional interchange gave Barça big problems, especially when Ronaldo and Benzema dropped into midfield and Marcelo and Carvajal came forward on the flanks.

Still, for the majority of the half, Barça were in control. Busquets, Xavi and Iniesta set the tempo, maintained possession, found pockets of space and covered the full-backs. Dani Alves and Jérémy Mathieu ventured forward only sparingly, wary of leaving space behind that Madrid could exploit. Gerard Piqué and Javier Mascherano played sensible passes, finding their more creative teammates in good positions to start moves.

Neymar’s goal was excellent, the result of a fine move and an exploitation of a weakness identified by this blog’s Clásico preview: the cross/cutback played in front of Madrid’s back four as it reflexively dropped back into the box, leaving space on the edge. That Messi miss followed another great passing move and cross from the right, and in the 28th minute Neymar had another huge chance after yet another break down that side.

Barça’s problems began when they became broken in defensive phases almost immediately before the penalty award. The defence dropped too far while the strikers pressed high and the midfield was repeatedly caught narrow in between the two lines. Suárez and Neymar rarely tracked Marcelo and Carvajal back and consequently Madrid’s full-backs were always available when Madrid needed a passing option to keep a move going or to change the angle of attack.

Iniesta and Piqué have been criticised for their errors in giving away the penalty, but it would all have been avoided had Barça not been in a very poor defensive shape when Madrid’s attack started, with Carvajal afforded thirty yards of space and all the time in the world to assess his options while carrying the ball forward. Needless to say, if you repeatedly give a side of Madrid’s quality that sort of time and space, even when the ball is with their right-back, keeping them out will be extremely hard.

Once Madrid had equalised, everything changed. The home side grew in confidence and half-time seemed to arrive just when Barça needed it. However, it was clear as soon as the second half started that Barça had lost their rhythm and that they were going to find it very hard to cope with a Madrid side that was flying. Xavi and Iniesta seemed flustered and overworked pulling wide, no longer getting forward into central zones to support Barça’s attacks and struggling to get back to cover Madrid’s ferocious advances.

Errors crept into Barça’s game. The focus on Madrid’s second goal will be on the mistakes at the corner that allowed Pepe a free header on goal from eight yards, but origin of the attack that led to the corner itself was more worrying.

Barça seemed to have everything under control in Madrid’s half. Iniesta, Xavi and Messi exchanged passes in front of Modrić and Kroos but found no forward passing options available. They went back to Mascherano, who played an assertive forward pass to Neymar’s feet. Spooked by Carvajal closing from behind and Modrić and Kroos rushing at him in front, Neymar played a careless pass back that Messi and Busquets could have picked up, but both were caught flat-footed and it rolled to Benzema.

Busquets was turned and suddenly, after a one-two with James, Benzema had played in Ronaldo, who was in acres of space. Piqué, Mascherano and Alves were back in covering positions but they were exposed. All involved in the turnover bar Iniesta jogged back or simply stood and watched as Madrid countered. Piqué blocked the shot and it went out for the corner, and the rest is history: horrible marking, a silly attempt by Alves to con the referee into giving a free-kick and a free header for Pepe.

What happened next was brutal. Xavi and Iniesta simply couldn’t cope with the physicality of the game – their roles meant that they had to contribute more in attack as well as defence and neither had the stamina or the pace to play wide of Busquets, who was left horribly exposed – and Madrid seized control. Barça suddenly looked one-paced and positionally rigid, their defence was there for the taking and Madrid’s fast and fluid attacks were devastating.

The attitudes of both sides’ forwards to their defensive work contrasted strongly from this point. Messi, Neymar and Suárez did almost nothing in the defensive phase besides showing Madrid’s passes wide, whereas Benzema made sure he always stayed close to Busquets and Ronaldo became a man possessed, dropping into fill gaps in midfield wherever they came up. The counter that led to the third goal after Ivan Rakitić’s disastrous delivery and a huge error by Iniesta came after Ronaldo had blocked a cross by his own corner flag. When Cristiano Ronaldo is outworking your forwards, you’ve got big problems.

Barça’s strategy ended up playing into everything they know Madrid are good at. They dallied in midfield and allowed Madrid to get back into position. They passed the ball to players who didn't want it, inviting Madrid to force errors. They overcommitted even at set-pieces, which is obviously suicidal: countering from opposition corners could hardly be more associated with Madrid and impotency from attacking set-pieces could hardly be more associated with Barça, but still they sent everyone forward and left Busquets and Mascherano back to deal with the inevitable sea of white that flooded towards them immediately afterwards.

Once Madrid were two clear, Barça’s structure deteriorated even further. The strikers became basically unreachable and Messi started playing in front of the defensive lines rather than between them. The midfield had no forward passing options besides the full-backs and the full-backs had no real options besides coming back inside. Barça’s moves went nowhere.

Lucho needed to change it with his substitutions but his changes were unlucky or came too late. Rakitić was desperately needed to replace Xavi, but after his corner led to the third goal he was clearly spooked and repeatedly made bad choices. His wide positioning in possession left Busquets outnumbered at turnovers, and when he came inside to support him, he exposed Alves.

Suárez played well for the first half hour but should arguably have been replaced at half-time. He rolled Sergio Ramos twice in the second half, but neither dribble was in a dangerous position and he was clearly too tired to track Marcelo, who was killing Barça at transitions. Pedro should have come on before it was too late.

Once Iniesta went off injured and Sergi Roberto came on, it was clear that Barça’s race was run and it was all about damage limitation from then on.

Despite the suggestion that there is now a clear gap between Real Madrid and Barcelona, this was a match decided by fine margins. The Messi and Neymar misses at 1-0 would have changed everything – although the same could be said of Benzema hitting the woodwork twice in a few seconds at the same scoreline – while Piqué’s handball for the first Madrid goal, Alves’ gamble that the ref would blow the whistle if he simulated a foul instead of marking for the second and the catalogue of errors led to the third swung the game away from Barça.

That being said, Luis Enrique’s system was again shown to be flawed and the Barça manager has work to do to make sure that other big sides don’t find it so easy to play his side when they’re losing. The front two remain prone to becoming static in central areas and they’re uninvolved in the defensive phase. Put simply, they were hard to find for the midfielders and easy to bypass for the opposition.

Messi is more involved in this system, but his impact is relatively easy to limit. He is repeatedly forced into areas where he can’t play a key pass or take a shot without taking on three or four players every single time he receives the ball and his tendency to come deep to get the ball when things are going badly makes him much less effective.

Once they needed to chase the game, Barça’s midfield became unbalanced and impotent. Xavi and Iniesta and then Rakitić and Sergi Roberto were hugely overworked and Busquets went from being composed and influential to exposed and overrun. The latter has been criticised strongly by several writers, but how well is anyone going to do when they’re constantly outnumbered?

It must be reiterated that Barça’s first-half build-up was incisive and effective, but in the second it became convoluted and counterproductive. Instead of supplying the front two and making chances for them to score, the midfield often dragged them out into wide areas, where they too couldn’t attack with any real purpose. With Messi holding back and no runners coming from midfield, Suárez and Neymar had no forward passing options.

In contrast to Barça’s needlessly complicated system, the beauty of Madrid’s was its balance and simplicity. Kroos and Modric were at the heart of everything, playing with better positional discipline than we have seen them display before for Madrid, while their passing was inevitably near perfect. Isco and James weren’t completely diligent defensively, but they were very energetic and their intelligent running at transitions gave Madrid’s forward bursts structure.

While Ronaldo and Benzema did the most damage, the key men were Marcelo and Carvajal, who were left almost completely unattended and allowed Madrid to keep the pressure on Barça in exactly the manner that Barça failed to do when they needed spare men to keep Madrid pinned back.

It’s worth stating again that despite the nature of this defeat, it wasn’t a total disaster. Barça aren’t finished and nor are Messi, Iniesta, Busquets and Luis Enrique, as many would have us believe right now. On another day it would have been a very different result, but individual errors put them under pressure and exposed the worst side of Lucho’s tactics. Under those circumstances, a defeat was unavoidable.