Napoli's 3-4-3 or 'Trident', as it is known in Italy, almost carried them to the Champions League QF and through most of the first half of last season. Napoli's focus was on numbers and counter-attacking, A quality that can help win points.
So let's look at the history of 3-4-3... Bielsa, or the mad-man in the spectacles, brought 3-4-3 to my attention back when he used this formation at the world cup with Chile (but since moving to Bilbao he moved back to a 4 man defence). Napoli were famous for using it all through the campaign gone by and Wigan used it to keep them in the top tier, while Liverpool have certainly toyed with it. Now many commenters on the blog have been calling for it, so using the Napoli Model, I will attempt to explain how 3-4-3 would work at Chelsea...
So here is the XI:
GK- Petr Cech
LCB- John Terry
CB- David Luiz
In my proposed 3-4-3 formation, these two centre backs will continue playing as they do in the 4-2-3-1 formation.
RCB- Branislav Ivanovic
Chose him over Cahill because his strength is a quality that can help him as a CB opposed to a RB. also Cahill is very similar to terry and a mix in skills would be the key to a successful defence. Brani wouldn't have to worry about attacking or pushing forward for most of the time as he will be a CB most of the time and he can leave the set-pieces to Luiz and Terry.
LM- Ashley Cole
Fullbacks with both attacking and defensive strengths are essential to 3-4-3. So let's compare Cole to Zuniga... Cole can drop back into defence with no problem and hold the line but 3-4-3 also gives him more chances to dart forward and give more support on the wings. A link is needed between the attack and defence and Cole can do this, operating as the overlapping fullback.
CDM- John Obi Mikel
Despite being a CDM in 3-4-3 Mikel would still hold the line in 3-4-3. Just like Walter Gargano, Mikel's job would be to sit in front of the back 3 and win the ball before distributing the ball to the attacking players. So his role will be similar to his current one.
CM- Eden Hazard
Eden Hazard as Gokhan Inler, how does this work you say? Well Hazard definitely has the distribution attribute that Inler has and his dribbling can link the the Attack (Trident) and the midfield. However my only worry is that Hazard doesn't have the defensive attributes Inler has and you might argue Lampard or Meireles would be a better fit.
Ramires' end-to-end runs and stamina makes him a perfect fit on the wing. Ramires' pace can be utilised to launch counter attacks and even though he may not be an ideal RB, his defensive mentality can help him slot in back in defence.
And now the trident...
LW- Juan Mata
Mata's creativity and slick dribbling means he can be a perfect fit for the 'Hamsik-role'. Which basically involves getting past defenders before passing the ball onto another forward. Mata can also have a punt within the box and get the ball into the CF and before you start screaming that Mata is a CAM, hamsik usually drifts behind the striker and this is another purpose Mata can fulfil.
CF- Fernando Torres
Who else can we put in this spot? We have no other choice really, studge is too one-footed to play this role and Lukaku hasn't even adapted to the PL yet. Looks like Nando is our only option. However, there is a beacon of hope. Nando has shown his dribbling skills in recent weeks and his ability to get off the mark quickly with the ball to get past defenders. That's the biggest secret to Cavani's success. Of course he'll have to work on his finishing because right now he isn't taking his chances (which lead to his own downfall) but if he can beat keepers in a manner similar to the way he beat Valdes and De Gea, I'm sure he'll be banging in the goals in no time.
Both players are very Similar but it may be worth taking the gamble on Hulk if we ever play 3-4-3. Why? Because he is similar to Lavezzi. He has both the strength and pace to Launch the counter-attacks down the right flank with Ramires and the eye for goal to convert with the use of his inside foot or likewise a cross or pass into a hungry Fernando Torres.
Strengths: 3-4-3 is very much a Counter-attacking formation. The aim is to get the ball onto the forwards. However unlike other counter-attacking setups, 3-4-3 requires quite a large part of possesion. This means that the attackers will hold onto the ball for the most and get a lot of chances (which can only help Torres). 3-4-3 also means that because the attack hold up the ball for the majority of time, meaning the opponents get very few chances. The attacking calibre of my proposed formation is of the same Calibre as Napoli's but the defence is even greater. Meaning this side is less exposed than the Napoli side that faced us.
Weaknesses: 3-4-3 is very demanding on the Attackers and not having depth in attack killed Napoli's campaign near the end of last season, so rotation will be ideal. Sturridge and Malouda are the only back ups I can think of for this formation and relying on them may be too demanding on them. Also the 3-4-3 formation is exposed and it is common for opposition sides to convert from very few oppurtunities. The three man defence is not the best at handling threats from the flank but I'm sure this isn't a problem with quality centrebacks who are very strong in the air. The only problems I can identify with the 3-4-3 formation I propose is that Hazard will have a tendacy to drop behind the strikers and fail to track back, leaving space exposed. The second problem is the fact that Ramires isn't the best fullback in the world and his tackles are timed a bit late and his poor vision could leave space exposed as well.
This is my simple breakdown of 3-4-3. I'm not saying that 3-4-3 is the future and we will never get anywhere without it but I'd like you to consider it (as many of you have alrady done). I also welcome criticism and encourage you to indentify flaws (probably loads in there).