Shift to 3-5-2 provides Chelsea a boost but not a solution for all their problems
Antonio Conte's most impressive quality as a coach is his tactical flexibility.
The Italian isn't tied to a particular formation and adapts his system to suit his squad rather than the other way around -- having arrived in England in the summer of 2016 intending to play 4-2-4, he quickly switched to 4-3-3 before shifting to the 3-4-3 formation that transformed Chelsea from flawed Premier League also-rans to runaway champions.
This season, in response to Chelsea's early setbacks, he has leaned on another "solution": the 3-5-2, the system that has provided the foundation for his team's best performances of the campaign against Atletico Madrid and Manchester United.
Despite its merits, however, there is also cause to think that 3-5-2 isn't the antidote to all of Chelsea's problems. ESPN FC runs through the pros and cons:
It helps solidify the defence
Chelsea's record in the eight matches they have started with 3-5-2 this season is W5 D2 L1, with the sole defeat coming against Manchester City. Given that the list of opponents also included Tottenham, Atletico, United and Liverpool, that is very impressive.
They conceded more than one goal in only one of these games -- that madcap 3-3 draw with Roma at Stamford Bridge in October. It seems more than a coincidence that this was the only one of the eight that N'Golo Kante missed.
An extra midfielder, whether it be Cesc Fabregas, Danny Drinkwater or even David Luiz, clearly provides more protection for a defence that has changed much more frequently than last season due to a combination of early-season suspensions and the form of Antonio Rudiger and Andreas Christensen.
It makes Fabregas viable as a starter
At this stage of his career, the 30-year-old Fabregas is a liability in a two-man midfield. He lacks the mobility and the positional sense to snuff out opposition attacks in the early stages, and his partner invariably ends up overworked.
With two men around him, however, the Spain international is unleashed to pass, probe and slice open defences with quarterback-style balls over the top. Those abilities make him one of the most prolifically creative players of the modern era, and utterly invaluable to Chelsea.
It addresses the main weakness of 3-4-3
The risk you run with setting up in a 3-4-3 is being outnumbered in central midfield -- particularly if your wing-backs drop deep to form part of a back five when out of possession, as Chelsea's frequently do.
Covering the entire width of the middle of the pitch is a very demanding brief for two central midfielders, particularly against talented and intelligent opposition. The fact that Chelsea were made to pay so infrequently last season is testament to just how exceptional Kante is. Without him the system is fatally flawed.
In a 3-5-2 the burden is eased, and Chelsea also find it easier to control possession because every player behind the attacking line has an extra passing option when they get the ball.
It leaves more attacking options on the bench
Conte has made no secret of his frustration at Chelsea's lack of squad depth after a frustrating summer transfer window. Up front is one of the thinnest areas, with Michy Batshuayi the only senior cover for Alvaro Morata and not fully trusted.
Switching to 3-5-2 leaves both Pedro Rodriguez and Willian outside of Conte's strongest XI. Both have demonstrated an ability to score or create from the substitutes' bench, and having them there gives Conte powerful options to turn matches that are getting away from Chelsea.
It creates more pressure for Hazard to do everything
What you gain in defensive solidity from the 3-5-2, you lose in attacking presence. Eden Hazard and Morata are talented and intelligent enough to make it work, but both are more dangerous when given a third forward to play with.
"The only player around me was Morata, so if we wanted to win we had to do something together, just me and him," Hazard admitted after the Liverpool draw. He was spectacular early on, but it was no surprise to see his influence wane with the burden of having to beat several defenders every time he got the ball.
Hazard is always one of the most fouled players in the Premier League, and deploying him as the only link player to Morata allows opposition defences to focus on him even more -- a bad thing for him and for Chelsea.
Starting Fabregas means losing a supersub
Last season Fabregas registered more Premier League assists (12) than any other Chelsea player despite starting just 13 games. His influence on the final 20 or 30 minutes of matches, when legs tire and spaces on the pitch typically grow, was devastating and often decisive.
Starting him more regularly means losing that freshness in what can be the most important part of a game. It is also, at the age of 30, probably not the ideal role from a physical perspective at this stage of his career.
Conte doesn't have the midfielders to do it regularly
With everyone fit, Conte has four senior central midfielders to pick from: Kante, Tiemoue Bakayoko, Fabregas and Drinkwater. (He's already stated that he doesn't see Luiz as a regular option there.) Starting three means having just one on the bench, and leaving Chelsea precious little room for rotation during a crowded schedule.
It becomes harder to keep Pedro and Willian happy
Willian has been disgruntled at his lack of starting opportunities for some time now, and until this week it looked as if his frame of mind was severely impacting his form. Pedro didn't leave Barcelona, the club of his heart, to sit on the bench somewhere else, but that is where a shift to 3-5-2 leaves both.
Then again, Conte said last season that he doesn't care about keeping his players happy, so such disgruntlement is unlikely to weigh heavily in his decision.
Liam is ESPN FC's Chelsea correspondent. Follow him on Twitter: @Liam_Twomey.