Most teams develop a solid defensive scheme and stick to it, only tweaking it slightly to suite the opponent. In recent years however, we have seen two examples of teams who were willing to radically change their defensive structure depending on whether the opponent was playing with two strikers or one. These two examples are Greece under Otto Rehagel and Chile under Marcelo Bielsa.
TWO SIDES OF THE SAME COIN
Greece and Chile could not have been any more different in their defensive philosophies. Chile favoured an intense pressing game as outlined here and Greece defended deep and narrow using a strict man marking system. However, they both used reactive defenses where the goal was to always have a spare man at the back. If the opponent played with two strikers, they would react by playing three centerbacks. If the opponent switched to a one striker system they would react by playing only two centerbacks and bringing on an extra midfielder. Greece used this strategy to win Euro 2004 and Chile over-performed in their World Cup qualification by always having an extra man in their backline.
This strategy requires a team to have versatile defenders who can play as midfielders or the manager would have to make substitutions every time the opponent makes tactical changes. Bielsa was clearly willing to do this but Rehagel tended to stick to his guns. So far I have yet to see a club team use this strategy. Glasgow Rangers switched to a deep 5 man defense for their Champion’s league games but they used this strategy against one or two strikers so it was not really reactive. Their goal was just to have as many defenders as possible. Sunderland recently switched to a five man defense against Stoke but this seemed to be a one-off to cope with a unique set-piece threat. Liverpool are an intersting case as they switched back to two centerbacks against Wigan’s one striker formation but it is too early to say what Dalglish’s approach is.
Even though this strategy works quite well it is not without problems. Chile struggled when playing against “nominal strikers”, that is strikers who started from wide positions. They did not know whether to treat this player as a striker or as a midfielder. This disrupted the reactive defense as Chile would either end up with too many defenders or not enough. Bielsa’s use of midfielders as centerbacks also left him at a disadvantage during set plays, something that was well exploited by Brazil. Otto Rehagel later abandoned the reactive defence in favour of a typical four man backline, maybe feeling he did not have the right players after his experienced defenders retired. There is also the problem of having to predict whether your opponent will line up with one or two strikers, something that requires extensive scouting and a bit of luck.
The reactive defense has the huge advantage of always giving a team one and only one extra man at the back. More than one would lead to the team being too weak in midfield and the centerbacks getting in each others way. So far this strategy has not been used by any club side I am aware of even after the over-achievement of Chile and Greece internationally. It probably has not caught on because managers do not want to have to react to every change that the opponent makes and the strategy has been shown to not work very well against nominal strikers. That being said, this season Rangers and Liverpool have shown the advantages of having an extra man in defense so it is not out of the question for teams to change their thinking.