A strange statement, you may think, considering the two Manchester teams sit first and second in the Premier League and have conceded the least number of goals in the division.
They have both had 20 scored against them and the big difference between the two is really at the other end of the pitch and the number of goals scored whereby City have 79 and United a mere 53.
This of course, as everybody knows, has contributed greatly to City now having an almost unassailable lead of 13 points whilst still having a game in hand.
So how good are the two defences which are, according to statistics, the best in the top flight?
Surprisingly, they are not as good as their figures suggest.
Manchester United have not had a settled back four all season and have included, at various times, Antonio Valencia and Matteo Darmian at right back, Victor Lindelof, Chris Smalling, Phil Jones, Marcos Rojo and Eric Bailly in the centre back positions and Ashley Young, Luke Shaw and Daley Blind at left back.
There is no way a defence which has been changed as often as this one should be producing the kind of statistics it has done this season. So how is it doing it?

David De Gea – The main reason Manchester United have a good defensive record
Well, one reason is David De Gea. On the frequent occasions United’s defence is breached, he is a very difficult man to beat. Now recognised as the best goalkeeper in the world, he has had to prove himself far more often than should be necessary at a top team like United.
Many a time, when the likes of Young or Valencia, neither of whom are defenders, get exposed or find themselves out of position, it is De Gea who comes to the rescue. Equally, when Smalling or Jones make one of their all too regular mistakes, it is the goalkeeper who saves the day.
It is probably fair to say that, without David De Gea in goal, United would have conceded at least five more goals this season and probably more!
Another factor in their defending is the manager. José Mourinho knows how to set up a team not to lose a game. That isn’t to say he never tries to win but his organisational skills appear to get the best out of some pretty average players when he is determined not to lose.
Just letting them know where they should be and when they should be there seems to have worked wonders with some of United’s “defenders”.
He also picks a team whereby the midfield is capable of defending so, quite often, to get through on goal means the opposition have to get past seven or eight defensive-minded players!
In truth, we still think there will be new arrivals in summer for a couple of the defensive positions as his ageing wingers cannot continue to get away with their non-existent defending forever and a quality, commanding centre back is required to play alongside either Lindelof or Bailly.
Manchester City, on the other hand, have a good defensive record due to the fact that they don’t need to do much defending!
When they have, on average, 71% of the play in any given match, it doesn’t give their opponents much opportunity to attack them simply because they don’t have the ball for much of the game!
A lot was made about the many absences of Vincent Kompany over the past few years and it was always perceived to be a problem when he didn’t play. Not any more. He is still a great player and it is good to see him in the team but he isn’t missed as much as he used to be. Why is that? Has Pep Guardiola bought competent replacements? Not really.
Nicolas Otamendi arrived before Pep and, whilst he has undoubtedly improved under the Spaniard, he still wouldn’t get into a Premier League best eleven.

Aymeric Laporte – A recent arrival at The Etihad
John Stones is a promising young defender but is still a work-in-progress and Aymeric Laporte has only just arrived at the club. So, apart from in the two full back positions where newer models have been brought in, nothing much has changed in the City defence.
No, what has changed is the philosophy. The team is now picked with the objective of winning every game they play.
So other teams may attack City but it won’t be very often and this is why the defence looks good.
On the one occasion that their defence was seriously put to the test this season, away at Liverpool, they failed and conceded four goals in their only loss of the Premier League campaign.
So the two Manchester defences do flatter somewhat to deceive but, as long as they keep winning football matches and, consequently, silverware, nobody really bothers too much although United’s need for improvement is greater than that of City.