Bundesliga
Borussia Dortmund are the only team in a top European league to have won all their league matches in 2023. A look at the statistics since the turn of the year gives an insight into what has made them so successful.
Having already shone a light on the players behind Dortmund's improvement, bundesliga.com crunches the numbers to explain why Edin Terzic's team are now the form side in Europe.
More wins
We'll start with the obvious one. Dortmund are in good shape because, on the whole, they keep winning matches. They started the calendar with ten consecutive wins in all competitions, including a DFB Cup round of 16 triumph over Bochum as well as a victory against Chelsea in the first leg of their UEFA Champions League last-16 tie - never before have Borussia won even their opening nine fixtures of a calendar year.
Their streak was brought to an end by a 2-0 defeat in their return European match at Stamford Bridge, which also saw them knocked out of the continental competition. However, by dismissing RB Leipzig on Matchday 23, the five-time Bundesliga champions equalled another club record.
Watch: Jude Bellingham on Dortmund's title ambitions
By making it eight league wins in a row, the current crop have managed something only Jürgen Klopp's title-winning side of 2011/12 have done before during a single campaign. Dortmund teams coached by Terzic and Marco Rose - across two seasons in 2021 - also had eight consecutive Bundesliga wins.
The winning run has naturally had a major impact on Dortmund's position. Before the winter break, they were sixth in the table and nine points adrift of league leaders Bayern Munich. Now, that end-of-year points difference with Bayern has been completely erased.
More prolific
Dortmund only trail Bayern in the table on goal difference, but the 1997 European champions have cut the gap in that regard too. No team has scored more goals than the 22 Terzic's men registered in the first eight league games of the year. Mainz - third in the form table over the same period - have 19, while Bayern - fourth on form with 15 points from 24 - have 17.
Watch: All of BVB's Bundesliga goals so far in 2022/23
Die Schwarzgelben have had the most shots at goal - averaging close to 17 per game this year - while they have become much more clinical too. Before the winter break they were, along with bottom side Schalke, the least efficient team in the Bundesliga - scoring 3.8 fewer goals than would have been expected given their attempts at goal. Now they are the most efficient - netting 7.7 more times than would have been expected given their Expected Goals (xG) rating.
Squad contributions and successful substitutions have also played a part. A league-high 10 of Dortmund's goals this season have been netted by players who were introduced from the bench during a game.
Substitutes have scored five times for Dortmund in the first eight Bundesliga games after the winter break, with Gio Reyna getting three of the goals. These included a decisive blow in a 4-3 victory over Augsburg on Matchday 16 and a last-gasp winner at Mainz on Matchday 17.
More set-piece goals
Dortmund have been one of the most dangerous teams from a dead ball too. They have 10 set-piece goals this term - with seven of them coming since the turn of the year.
Watch: BVB see off Leipzig with two set-pieces
Terzic's team had only one goal from a free-kick before Christmas, but no team has scored more times from that situation in 2023. It proved the undoing of rivals Leipzig, too, with Marco Reus converting from the penalty spot prior to Emre Can turning home from close range after Julian Brandt's delivery was hoisted back towards goal by Jude Bellingham. That effort means Dortmund have now found the net from four free-kicks this year.
More difficult to score against
Bayern still have a sizeable goal-difference advantage over Dortmund, but that figure has been cut by seven in the calendar year.
For as well as scoring more freely, Dortmund have been harder to score against as well. No team has conceded fewer than their seven concessions from the first eight league games in 2023.
While BVB have allowed 104 shots - only six teams have allowed more - goalkeeper Gregor Kobel has been a reassuring presence. He's saved a league-high 27 attempts in 2023, compared to a total of 36 in 15 league matches before the winter break.
Watch: Kobel is in great form
More running
Last season's runners-up had the third-highest possession percentage - 55 - before the winter break. That figure has improved to almost 57 over the last eight matches, comparing favourably with Bayern's average of 59 per cent.
Dortmund are running an average of three-and-a-half kilometres more per game in 2023 - 116 compared to 112.5. They're also showing higher numbers in terms of sprints and intensive runs.
Hard work is clearly paying dividends - but can they sustain it at these levels? If they do then there could be more silverware in the trophy cabinet come the end of the campaign.