If Ancelotti's first two preseason games are anything to go by, he is prepared to make a gamble few other EPL managers would-- he might play two strikers up top. Admittedly, it is a bit premature to assume a definite formation from a coach that should exhibit tactical flexibility, but Ancelotti is definitely considering the 4-4-2 diamond.
"I would like to play with two strikers because we can put more zonal pressing," said Ancelotti. "I want to follow this way." (
Guardian)
The general trend in recent years has been to use fewer specialist strikers. Many teams play with one striker (i.e. Arsenal. Liverpool). Roma, meanwhile, were the pioneers of a 'no striker' formation-- a flexible attack in which players rotate positions up front. Roma's success in some recent seasons lead some pundits to proclaim that the traditional striker was dying, in much the same way that the Riquelme-style playmaker seemed on its way to extinction. In the place of these players would arised a breed of versatile playmaker wingers and hybrid strikers, like Ronaldo, Messi, Tevez, and even Donovan. Why? The short version is that most modern football teams couldn't afford the luxury of two strikers-- they would be outplayed in midfield. Moreover, wingers were needed to pin down the opposition fullbacks, leaving little room for specialist playmakers.
There were some signs that this versatile attack was the direction that football was heading. Indeed, this year's Champion's League final seemed to prove the point. Manchester United put Ronaldo, a playmaker winger, up front because 1) he had wrecked havoc in the Arsenal defense up top and 2) his turn-overs and questionable defensive work rate made him too much of a liability to put anywhere else. Barcelona, for their part, mostly played their recognized strikers (Eto'o and Henry) in hybrid winger roles, with Messi given the freedom to roam about as a playmaker forward. Both teams lacked a traditional #10 playmaker; both essentially deployed playmaker forwards up top, with more traditional forwards shunted to the side.
However, the 4-4-2 is far from dead: the US recently reverted to two up top, and now Chelsea appears to be doing the same. The wonderous thing about Chelsea's change is that they possess, in Didier Drogba, the definitive target man. Drogba is the paragon of the sort of player needed to spearhead a one striker formation (though not, perhaps, a stikerless formation).
Though Chelsea's players may seem particularly well suited to a 4-3-3, the truth is they do have the players for a 4-4-2. Zhirkov can play the entire left sideline, so he is well-suited to a wide-midfield berth. Up top, Drogba (31) is probably in decline. He is also inconsistent, in the sense that Ancelotti may not be able to bring out the best in him-- after all, Scolari didn't. In Kalou and Sturridge, Chelsea possess one of the most underrated players in the division and one of the hottest strike prospects in the EPL, respectively. Finally, there is Anelka-- a player who finished top of the league goal scoring charts last year. (Admittedly, Anelka has also performed well on the right wing, one area where Chelsea seemingly lack a natural fit-- Essien is not really a right midfielder, and Joe Cole has gone missing. Accordingly, Le Sulk may continue to see the wide berth more than he likes.) In short, Chelsea have the personel to pull off a 4-4-2 and reduce their reliance on Drogba.
And more zonal pressing? What does Ancelotti mean by this?
Teams tend to have an easier time maintaining their shape in a 4-4-2. When a team playing a standard 4-4-2 is on defense, it is often possible to pause a game and see two clearly defined lines of four. A 4-4-2 diamond is slightly less robust, but still provides some defensive solidarity by distributing players across the entire field. It would allow the team to press the wings without shifting the midfield over and exposing the opposite side, or leaving gaps behind the fullbacks, things that can happen when playing a three man central midfield and flying wingers; however, the 4-4-2 daimond formation can also expose the lone defensive midfield in the center if Lampard fails to get back fast enough.
[Updated for clarity July 26]The issue is not so much that Chelsea are weak defensively in a 4-3-3 (they have quite a good defensive record), but rather that more pressing-- including by the strikers-- might wear down opponents and generate attacking opportunities. With a 4-4-2, there may be less pressure on the opposition full backs, and more pressure on the opposition center backs, who could be isolated and exposed by Chelsea's talented strikers.
However, changing the formation of an accomplished team will always be risky. Keep an eye on how this gambit plays out for Ancelotti.