As Antonio Conte’s blue army take a commanding ten point lead into the final break before the hectic title run in, it’s a suitable time to take stock as to what exactly they have achieved so far and what is left for them to accomplish.

This formidable side has followed an interesting path to where it is now, with a rocky start to the season as the Italian tried to find his feet before collapsing at Arsenal in September, which resulted in the coming of the 3-4-3 and the unrelenting push for the title.

The 3-4-3 has undoubtedly taken the Premier League by storm, when previously a three at the back formation has been described as unsuitable for the English game, particularly after Louis van Gaal’s United side failed to implement the Dutchman’s preferred formation which was impressive in the 2014 World Cup.

Conte’s 3-4-3 has been typified by a stout and unforgiving defence, marshalled by a reborn David Luiz. This, coupled with a devastating counter attack and an industrial midfield two has been the recipe for success and leaves the four-time champions just 21 points off Premier League glory.

However, the numbers can often tell a different story, is this run unsustainable? Or incredibly, is there, even more, to come from this side? we have a look at this question here.

Using Michael Caley’s expected goals model, we can read more into a team’s performance. Are teams being particularly clinical? Are teams getting away with what is a poor defence, because of below-par finishing from the opposition? We can answer questions like this using expected goals (xG).

Chelsea are scoring on average 2.1 goals per game as opposed to 1.5 xG. This tells us that Chelsea are scoring at an extremely clinical rate, 40% increase to be exact. This, on the surface, is worrying and unsustainable in the long run, however counter-attacking football generally provides better chances which could possibly be underrated in the xG model. Conte, I believe is aware of this, which can be seen in his usual change to a more balanced 3-5-2 towards the end of matches, which allows a more creative midfielder in Fabregas to flourish which could be what Conte envisages as a solution in the future.

In fact, Chelsea’s xG for per game is the lowest in the top seven which is a cause for concern for next season, although a lot of the situations in which Chelsea outperform their xG is winning games by two or three goals when the xG model only has the Blue’s winning margin to be one or two goals respectively. What we can take from this is although Hazard and co. do enough to win games, the gap is not always as big as the scoreline might suggest.

At the opposite end of the pitch, the numbers provide much more sustainable figures, with actual and xG both being 0.8 per game, a statistic unmatched in the league.

On a more individual basis, the case of Diego Costa stands out. A man who has, for the most part, left his dark side in the abyss that was the 2015/16 season. A blistering start to the first half of the season saw the Brazilian dominate the scorer charts and was, for many, in that period the best striker in the world. It almost seemed as if Didier Drogba never really left. It goes without saying that a goal in a 1-0 win is more important than a brace in a 5-0 win and in this regard the former Atletico striker has no competition, being the player who has directly contributed to more points than any other player this season. A statistic often not given enough importance when judging a striker.

Then came the rumours linking the Stamford Bridge favourite with China and his incredible form came to a stop. He is still contributing goals but everyone can tell he is not the same player that gave defenders nightmares in the tail end of 2016. Many people jumped to the logical conclusion, that the Chinese rumours unsettled him and his head was not in it anymore, but in fact, the numbers were showing that this dip in form was coming, Chinese rumours or not.

In early January when the rumours began, Costa had scored 14 goals from a measly 6.2 xG. He was outperforming his xG by 225%! To put this number in perspective, two of the greatest players the game has ever seen, Lionel Messi and Cristiano Ronaldo consistently outperform xG by 120-130%. No doubt the China factor played its part, but ‘the Guv’nor’ couldn’t perform his superhuman feats forever.

Looking towards the end of the season Chelsea appear to be on course for their fifth Premier League title. Although overperforming to some extent, the lead they have built seems unassailable, with numerous prediction models giving the London side over a 95% chance of lifting the trophy.

Twitter: Projected final EPL table after this weekend’s games. West Brom, Stoke and Southampton look like they have nothing… https://t.co/5dCpNe3qbX (@EightyFivePoint)

Conte has built a machine, with each cog playing its part. With Player of the Season performances all over the pitch from the likes of Costa and Eden Hazard to N’Golo Kanté, Luiz and even Cesar Azpilicueta means there is certainly much to be optimistic about, yet there is evidence for caution too, just like in 2014/15, the Blues are riding a wave but with a summer of investment promised, Conte can build for the future.