

As for the Bundesliga, it is just Bayern, and then everyone else. The league actually needs to be competitive, if you are going to call it the best.
La Liga has 3 incredibly strong teams.
In Serie A, there have been 514 games after 20 rounds (with 2 matches still to play with 4 teams still having played only 19 rounds). That works out to exactly 2.59 goals per fixture as well.
Magically, La Liga also works out to be 2.59
The Bundesliga has the highest goal count per fixture at 2.82.
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Of course there are limitations to this analysis. But as a whole, one would have to conclude that the attacking players in the premier league are superior than in Serie A. So if overall goals scored is the same per fixture, it would imply that English defences are actually better than Serie A.
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I also don't think the EPL is in decline. Recently EPL teams have not done that well in the champions league but I think that is partly as a result of the fact that the top 3-4 teams had been more equal than the top 3 or 4 in Spain or Germany (forget Serie A as its not even comparable) in recent years.
If the wealth in the EPL was concentrated into 2 teams like it is in Spain or 1 team as it is in Germany, they would probably win the champions league almost every year.
It just makes you realize the sorry state of Serie A. Juve has won the league 3 years in a row and is 7 points clear just past the midway point and the best any Italian team has done in the last few years is reach the quarters (thanks to an easy fixture against Celtic). This year Juve struggled just to get to the knock outs and can thank Atletico for playing out a draw in the last match.
