I watched Arsenal concede a goal to Spurs at the Emirates at the weekend and it struck me forcibly that Arsene Wenger has made absolutely zero progress in overcoming his biggest weakness throughout his years at the top.
He's not alone. Both Arsenal and Liverpool head into Champions League action tonight with badly organised defences and poor defenders. I cannot imagine either team actually winning the competition because they will meet teams in Europe that can defend.
I could easily extend that to the Premier League and point out that only one manager, Jose Mourinho, seems to have the required knowledge to set up a proper defence and say that Chelsea, and not Manchester City, Liverpool or Arsenal will win the title.
It has always been a mystery to me why Wenger cannot see that his attitude to defence and goalkeepers has cost him countless trophies. In a simplistic way, it's "we'll score more than you" and I don't know of any great team which prospered with an attitude like that.
All the greatest teams knew how to defend and even if they didn't necessarily have the best defenders in the world, the coaches had the knowledge they needed to organise them properly.
A good defence is always better than the sum of the parts and while it always helps to have top class defenders to man it, a manager can achieve a great deal with relatively ordinary players who know exactly what they should be doing and try everything in their power to do it.
It's Mourinho's ability to defend which, I believe, puts him above all the other managers in the Premier League at the moment and that's why I had a good laugh at Brendan Rodgers when he accused Chelsea of parking the bus in the crunch Premier League title decider in April.
"Anyone can do that", said Rodgers when very clearly, he couldn't.
Perhaps if he learned how to "park the bus" properly, Liverpool might have actually won the title. The accusation he threw at Mourinho was ridiculous and did nothing but underline his own ignorance of the art of defending.
I don't think there is any evidence that Rodgers has learned his lesson from what I've seen of Liverpool this season. They leak goals at the back and this time, they don't have Luis Suarez to balance up the equation. Likewise Wenger who continues to believe that somehow, if he gets more and more creative players on the pitch, it will be enough but it never is and it never will be.
I have no doubt at all that the general standard of defenders and defending has dropped considerably and steadily in recent years and why that should be I'm not really sure. Back in my day and up until the 80s, you would have three or four top quality centre-backs from all five national squads on these islands playing in what was then the First Division.
Right now, I don't see more than a handful in the Premier League and most of them are foreign but really, that is a different issue.
The talent drain caused by modern life and the temptations available to kids is part of it and big clubs now look for players in all four corners of the world. But they still don't seem to be able to find any defenders. But that's not the end of it. As I said above, it should still be possible to defend well even if you don't have really top quality players to use.
That work is done on the training ground and over time and with enough repetition, defence becomes instinctive and adaptable.
But the work has to be done and whatever Arsenal and Liverpool are doing when they're not playing matches, they are certainly not learning how to defend well.
Mourinho clearly drills his players and gives them certainty. Over all those years when his teams were criticised for being drab and too defensively minded, he was racking up trophy after trophy while others won nothing.
And when Rodgers threw a fit and lashed Mourinho for ruining his party with a wonderfully executed counter-attacking raid on Anfield at the end of last season, he would have been far better served by studying what Chelsea did on that day and basing his own defence around it for the future.
In many ways, we are spoiled with the quality of attacking talent on show in the Premier League in recent years. Some of the very best strikers in the world are on view and they draw the eye.
Last season, Suarez covered up a multitude for Liverpool and Rodgers and he was a great man to defend from the front. He chased and harried and set a great standard for those behind him.
Unfortunately, when it came to the high pressure games at the crunch part of the season, Rodgers lack of defensive nous and the poor defenders he had in his squad were exposed.
Now that Suarez is gone, the gaps at the back look even bigger and I really don't think Rodgers has the knowledge to fix it.