Why isn't Villas-Boas's philosophy working yet?

Rory Smith assesses how the Portuguese's style has got lost in translation at Chelsea

Andre Villas-Boas, the thinking went, did not need time. He did not need time at Porto, where he oversaw a transition from mediocrity to magnificence in just a few weeks. And he would not need time at Chelsea, or so it seemed, when he arrived to fulfil the simplest, starkest of briefs: a complete reinvention of the way the club played, the way the club won.

He was, of course, the natural choice: a 33-year-old in a hurry, the alchemist Roman Abramovich required, the manager who could replace Stamford Bridge's creaking base metal while keeping up a supply of gold sufficiently steady to sate his benefactor. That is what he did at Porto, after all. This time last year, they were champions elect, sweeping all before them. Chelsea, surely, would be the same.

Five months on, the revolution has been televised, and the revolution has been criticised. Chelsea's progress has been halting, uncertain. Only victory against Valencia tonight will stave off yet more talk of crisis. So why, after his gilded beginning, is the clock starting to tick on Villas-Boas?

Undermined in the middle

The Chelsea manager himself admits that the most important tactical facet of his Porto side was the rotation of his midfield. "Our No 6 sometimes became a more attacking midfielder and we tried to do that here," he says.

At Porto, the system worked like this: a 4-1-2-3 formation, in which Fernando, the Brazilian, nominally filled the deeper-lying defensive role. Joao Moutinho, Fernando Belluschi or Fredy Guarin were stationed ahead of him. Villas-Boas's twist, though, was that his system permitted his three midfielders to interchange that role at will, unbalancing their opposition, breaking forward unexpectedly, adding pace and urgency to attacks.

"We decided it doesn't work here, so that's one of the things I have adapted," he admits. "You lose a little bit of balance in the Premier League if you play that way. Transitions here are much more direct, making the importance of the No 6 to stay in position most decisive." The issue is that, in switching to a more static No 6 – initially John Obi Mikel, now Oriol Romeu – his side's sharpness has been blunted.

The high line and the high wire

English football does not react well to those who attempt to change its lexicon. Claudio Ranieri and Rafael Benitez never recovered from their perceived foibles of squad rotation and zonal marking; Villas-Boas may live to rue the phrase "high line".

The Portuguese is adamant Chelsea's defensive problems are overstated. "Is your organisation called into question because you have conceded four more goals than the leaders [Manchester City]?" he asked, bemused, last week.

It is not, though, the quantity so much as the quality of the goals that have caused concern. Fingers have variously pointed at the previously unflappable John Terry, the eminently flapping David Luiz and even Ashley Cole, but Chelsea's problems speak more of a system failing, rather than any of its constituent parts.

Villas-Boas is evidently concerned by the "relationship between the line and the goalkeeper". It is here that much of the confusion starts: Petr Cech is not a sweeper-keeper, meaning there is a huge area behind the defence – pushed up to press in midfield – to exploit. The absence of a specialist, trusted right-back means the line is split – Ashley Cole pushes up on the left, but the more defensive Branislav Ivanovic does not – and the team lacks balance.

The irreplaceable Hulk

Porto's defining characteristic was the speed of their transition: the rapidity with which the ball travelled from back to front. "There are different things [in my philosophy] that are related to building up from the back, opening up spaces in your build-up, the rotation of the midfield, the movement, the strikers working within the lines," says Villas-Boas, when asked to describe the central tenets of his teams' play.

All came together perfectly at Porto, and in a side built to maximise the talents of Brazilian striker Hulk: playing wide on the right but equally adept at coming inside or attacking the flank, his role was to occupy the opposition's left-back, dragging him out of position. The right-sided midfielder – Belluschi or Guarin – would then attack the space left behind, giving Porto a front four.

It is no wonder Daniel Sturridge is thriving under Villas-Boas: the young striker has, effectively, been handed Hulk's role. One problem, though, is that Sturridge tends to head to the middle rather than out wide. Another is that Chelsea do not possess players with either the instincts or the conditioning to get the ball to him at the speed at which it arrived for the Brazilian. Two years of Carlo Ancelotti's more patient style has created a side, more contemplative, more ponderous in possession.

One glance at Villas-Boas's ins and outs list is enough to bear that out: on the one, Salomon Kalou, Florent Malouda and Nicolas Anelka, all slow movers of the ball, and the other the likes of Eduardo Vargas, quick and direct. So too his behaviour on the touchline: Romeu makes far more risky passes than Mikel, but each one is applauded by his manager; each one is a little revolution in itself, a step toward the future Villas-Boas has planned out.