Despite sitting at the bottom of the EFL Championship, Derby County have the joint-best defensive record in the second tier this season. This may come as a surprise to anyone who watched the Rams play last season, as Derby's shambolic back line conceded 58 goals in 46 games, over a goal per game.
But what specifically has helped Derby turn it around?
Part of Derby's problems last season was a distinct lack of experienced centre backs. With Curtis Davies out injured, Derby relied on Matt Clarke and Andre Wisdom, with the latter only having two years of senior experience playing in that position.
George Edmundson and Teden Mengi were brought into the club in January, but both struggled to make an impact, with Mengi especially suffering at the hands of experienced attackers on a number of occasions.
With Davies and new-signing Phil Jagielka at the back, and with the experienced Richard Stearman in reserve, Derby have a number of solid options in the centre of defence. Davies particularly has been in inspired form this season, even managing to chip in with the winning goal against Stoke City.
Full-back & midfield relationship
The relationship between the two holding midfielders and the full-backs has been a huge part of Derby's defensive success so far this season.
Max Bird and Graeme Shinnie drop into the defensive channels, opening up space for the full-backs, whether it be Craig Forsyth, Lee Buchanan, Nathan Byrne or Festy Ebosele. This protection gives the wide players a greater license to go forward, fills the gaps left behind, and also provides an option to pass to if the attack breaks down.
To describe Derby's goalkeeping situation over the last three years as a "crisis" would be something of an understatement. The decline of Scott Carson, the inconsistency of Kelle Roos, and the confusion around David Marshall had caused Derby no-end of problems.
However, this season things seem to have changed. Roos has provided the best form of his career so far, looking much more reliable between the sticks. New recruit Ryan Allsop has also looked assured, conceding just a single goal in his first four games.
Having a reliable goalkeeper goes a long way towards having a successful defence. Derby fans will hope that the form of both of their goalkeepers will remain for the rest of the season.
The return of supporters
Now this may sound a little silly, but the return of supporters has clearly had a huge impact on Derby's team, not just the defence. However, that extra push late in games has been vital so far this season.
Derby had a habit of conceding late goals last season, and that has been mainly eradicated aside from a few notable lapses in concentration.
A number of players have commented on the impact that supporters have made, not least Shinnie who claimed that supporters were "so important" in helping them hang onto that 2-1 victory over Stoke City.
With the current circumstances of their ownership, Derby will lose the services of Jagielka in January. This will be a huge blow for the club, losing arguably one of its most influential players both on and off the pitch.
However, Polish international Krystian Bielik, who has operated in the centre of defence before, should return to first team action before Jagielka's departure.
Whilst not ideal, Rooney may be tempted to have Bielik operate in the heart of defence, allowing for Bird and Shinnie to continue their strong form in the centre of midfield.
Derby fans will be hoping that the ownership situation is sorted quickly, as it means they could squeeze another six months out of the veteran Jagielka.
Do you think Derby will stay up this season? Let us know in the comments.