Saturday night sees the seventh – and final – Clasico of 2011, and perhaps the one with the most tactical possibilities.

There are reasons for that on both sides. Real have played a more attacking game this season, and there’s less certainty that they’ll defend deep, park the bus, and invite pressure. Barca, on the other hand, play the same style of football as ever, but they’ve experimented with a new formation – 3-4-3, which they’ve used in over half of their league games this season. With few injuries and squads stronger than last year, it’s surprisingly difficult to predict the 22 players that will start this match.

This preview is divided into nine sections – four each looking at the two sides’ approach, formation, selection and specific tactics, and then a few key questions.

Real Madrid: approach

Tactics are determined by what you want from the game, and this is an extremely important consideration, especially for Real. They are currently three points clear of Barcelona with a game in hand, which will almost certainly become a six-point advantage once that game in hand is played. Jose Mourinho’s desire to establish Real as more of an attacking force this season is clear, but for this match, he might change, because a draw would do him nicely. It would preserve the theoretical six point gap; Real would still have the league title in their own hands, even if they lost to Barca in the return match.

Real’s assistant coach Aitor Karanka has denied they’ll settle for a draw – but then, of course he would. Real don’t want to be seen as negative, and they’re hardly likely to give away their gameplan. But unlike in the second league Clasico last year, or the Champions League, Copa Del Rey or Supercup matches (even if you count away goals, extra time or penalties) Real don’t have to win. A draw will be regarded as a positive.

Barcelona: approach

Logically, Barcelona’s situation is the exact opposite. Their players have been keen to stress the importance of winning this game to their season – Dani Alves says “our margin of error has gone.” Lionel Messi says “It’s vital we get a good result.” Pep Guardiola pointed out that saving the Euro is more important than the Clasico, but maybe that was because there was no way of avoiding how crucial this match is in pure football terms.

He isn’t used to going to the Bernabeu needing to win (even if they often have done). For the past three years the away leg of the Bernabeu was late in the season with Barcelona already in command of the title, whilst both the Champions League and Supercup first legs were away, with Barcelona knowing they could wait for the second leg to make the breakthrough. A win isn’t essential, but it’s more vital than usual.

Real Madrid: formation

Jose Mourinho has almost exclusively used a 4-2-3-1 formation this season, with the exception of the away trip to Valencia, when he compromised and selected a 4-3-3 shape instead. A 4-3-3 is not necessarily less attacking than the 4-2-3-1, but in Real’s case it is – it involves the removal of one of the front four and the insertion of another central midfielder, likely to be a physical, combative ball-winner.

It seems likely the 4-3-3 is his big game formation, and like last season, he won’t risk playing four attackers against Barcelona. The use of Mesut Ozil in the centre of the 4-2-3-1 for the 5-0 last season was a disaster and it seems highly unlikely Mourinho would risk being completely overrun in the centre again. Three disciplined, functional midfielders are required.

Barcelona: formation

The 3-4-3 or the 4-3-3? The 3-4-3 has been preferred this season, but might not get an outing here, for four main reasons. First, in Guardiola’s words, “If you don’t control the game, a defence with three can cause problems. And you can’t control 90 minutes against Madrid.”

Second, for reasons outlined previously on this site (and in combination with the first point), a back three is much better against two strikers than against one or three forwards. You want one spare man, and with Real likely to field a front three, that wouldn’t work.

Third, it hasn’t looked particularly convincing when Barcelona have come up against decent sides – against Valencia they reverted to four at the back, against Sevilla they didn’t score, against Milan they just about won, but looked troubled.

Fourth, there is the crucial fact that, midway through the Clasico series last year, Guardiola realised that Real were enjoying breaking quickly down the flanks, and ordered his full-backs to remain in position to stop those breaks. A back three might mean more space on the wings for Real to exploit, and although the system can be fluid to allow defenders to attack, it’s doubtful whether Barcelona want to be fluid in a zone where they’re up against Cristiano Ronaldo.

Real Madrid: selection

Ricardo Carvalho is injured which means Pepe, used as a forward-playing defender in a couple of the Clasicos last year, will be needed at the back alongside Sergio Ramos. That means there’s a space in the probable three-man midfield – Xabi Alonso and Sami Khedira will start, and might be joined by Lassana Diarra, who played when Real went 4-3-3 against Valencia.

There’s also a possibility Diarra could start at right-back, where Alvaro Arbeloa is returning from injury, but this is unlikely. Another very interesting factor is the use of left-back Fabio Coentrao at right-back in Real’s win at Sporting Gijon last weekend, and that could be very useful against a player like David Villa, who will look to come inside from that flank onto his right foot (if he starts) – in fact, he scored a cracker in the Supercup in that very situation.

Upfront, the choice is between Karim Benzema and Gonzalo Higuain. They’ve both started seven league games, but are very different players. As Sid Lowe outlines, “Benzema is far more technical, a better player in the absence of space, Higuaín applies greater pressure and is swifter on the break. The decision as to how Madrid play…will go a long way to deciding who Madrid play.”

But will either play? It’s entirely possible that Ronaldo could be used as the lone forward – that’s how he played when Real triumphed in the Copa del Rey final, and in the first leg of the Champions League semi (when Real lost, but the system worked well until Real went down to ten men). That would leave Angel Di Maria on the left up against Alves, and Ozil breaking from the right. If Real want to counter-attack, this might be a better solution than using Higuain.

Barcelona: selection

Guardiola has various options throughout his side, but arguably more fuelled by uncertainty than a plethora of impressive options. At the back he will want pace. There are fitness concerns with both Gerard Pique and Carles Puyol, and Javier Mascherano has been more of a regular at centre-back this season. It’s probably either Pique or Puyol alongside the Argentine, with fitness a greater factor than style.

In midfield, Sergio Busquets and Xavi Hernandez are sure starters, and Andres Iniesta will definitely play. But will it be in midfield? If Real are going with physicality in midfield, the use of Seydou Keita will interest Guardiola so Barca aren’t overrun, with Iniesta moving forward into the front three. From there, Iniesta would come deep and turn the midfield three into a midfield four, recreating a loose diamond, as in the 3-4-3.

Only Messi is a certainty for the front three, and his position is uncertain – he could play as a false nine, or on the right, as against Milan. He will probably be used with one wide forward (Pedro Rodriguez, Alexis Sanchez, David Villa, Isaac Cuenca) and one deeper, more central converted midfielder (Iniesta, Cesc Fabregas, Thiago Alcantara). Three forwards might be too direct and not strong enough in midfield, whilst Messi and two midfielders wouldn’t offer enough penetration. Fabregas and Pedro is a decent bet – but Pedro might not be fit. Cuenca would be a bold move, but he’s the closest to what Pedro offers, in terms of excellent positioning and movement from wide.

Real Madrid: tactics

The key question, in the entire game, is this: will Real press high up and be aggressive, or will they sit back and invite pressure? The likely answer is a combination of both – in El Pais, Diego Torres predicts that Real will close down Barcelona early on, especially at goal kicks and throw-ins, and then revert to sitting deep after half an hour.

That seems a decent approach – Mourinho doesn’t want Barcelona to stamp their authority upon the midfield early on, like in the 5-0, but equally his players probably won’t have the capacity to press and close down for 90 minutes. If they take on Barca at Barca’s game, they’re likely to come off second best.

Dealing with Messi is the key question – in the Supercup Mourinho told Carvalho to stick to Messi when he dropped deep, meaning Real narrowed into a back three. Either Pepe or Sergio Ramos could conceivably do the same, and they’ll probably take it in turns to follow Messi depending upon which side of the pitch he works in.

In midfield, Alonso will sit deep and sweep up behind Diarra and Khedira, which will work well when Real win the ball – he should have time to spread the play to the flanks and prompt counter-attacks. Diarra should be tracking Iniesta, Khedira will close down Xavi and possibly look to pressure Busquets too.

With the ball, Real will break quickly from back to front, with combinations from the front three. Khedira will probably be given license to join them, and Marcelo will look to attack, especially if Barca field a narrow right-sided attacker – like against Milan, when they were vulnerable to attacks down that side.

Barcelona: tactics

Barca will dominate possession. That’s what they want – and it’s probably what Real want too, as Ajax coach Frank De Boer observed this week, to aid their counter-attacking. Guardiola last season declared that Real were the most effective counter-attacking team in Europe, and although they’re more varied in their approach play this season, they’ve also become even better at counter-attacking.

Therefore a cautious approach in possession is likely – Barcelona will look to hoard the ball whilst limiting forward runs. This will deny Real the opportunities to break into space, but will also tire Real if they look to press early on. Watch for the forwards dropping into the midfield to help retain possession, but how much will this hamper their ability to penetrate the defence?

Busquets is an extremely important player. It’s not immediately clear which Real player will close him down (if it’s Khedira than Xavi will either (a) be free, or (b) will be tracked by Alonso, which means he’ll drop deeper and pull Alonso a long way up the pitch, leaving space between the lines for Messi). Busquets should get the most amount of time on the ball of any midfielder or forward, and has to be intelligent and resourceful with his passing, looking for free players.

There must be both width and depth to their play. When Barca struggled against Real last season it was when Messi came too deep into midfield and Barca had no forward options. When they’ve struggled this year, it’s because they haven’t stretched the play and have funnelled everything through the centre.

Key questions:

Assuming Real switch to 4-3-3 and Barca also play 4-3-3, there are five key questions, or groups of questions, which will decide the game.

1. Will Real press? And if so, for how long?

2. Will Busquets get time on the ball? And if so, how well does he take advantage of this?

3. How much will Barcelona focus upon retaining possession, and how much will they look for penetration? And how will this change over the course of the game?

4. To what extent can Alonso help to dictate the tempo and rhythm of the game, and prompt quick counters? Will Barcelona look to close him down?

5. Will Messi play on the right or in the centre? How will Real deal with him? Will it be enough to stop him?

Five key issues, but this is a game with hundreds of questions, which should result in a fascinating contest.

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