Regardless of the positional history of pundits, defending is often the first thing to be analysed. It's easier -- and probably makes for better television -- to find fault, rather than highlight the positives and, when analysis contains replays of goals, focusing upon defensive blunders is inevitable.

But Manchester United manager Jose Mourinho, when quizzed last week about Wayne Rooney's career ahead of his Old Trafford return, implied the opposite.

"I think Wayne spent probably 10 years of his career in a different Premier League than you have now," Mourinho said. "A Premier League where it was easier to score goals, not just because of the difference between the top teams and others, but also because of the profile and the tactical interpretation of the competition. I think this Premier League is much more defensive-minded and much more difficult."

So who is right? The pundits who claim scoring goals is easier or the manager who says scoring goals has become harder?

A number of factors are at play, so let's start with the most common assertion from pundits, which is that defending is getting worse. It is a claim that is highly questionable when you watch any highlights montage from the 1990s, when defenders frequently scuffed clearances to opponents and miscontrolled the ball in dangerous situations. The overall standard of defending probably has not declined significantly.

What is true, however, is that today's best are not as good at the "traditional" centre-back duties as their predecessors. Genuinely outstanding defenders are few and far between and the majority are more comfortable when playing a long way outside their penalty area, pressing opponents quickly, catching them offside or nipping in early to intercept the ball.

Tottenham duo Jan Vertonghen and Toby Alderweireld are the best examples of this modern trend, while Arsenal's Laurent Koscielny is in a similar mould and another exponent, West Brom's Jonny Evans, is receiving some belated appreciation and interest from bigger clubs. But these players aren't as comfortable defending when closer to their own goal.

Meanwhile, towering, physically dominant defenders are increasingly a rarity. With men at the back increasingly expected to start passing moves and not simply break up those of the opposition, it is inevitable that this is offset by a drop in traditional defensive skills.

Wayne Rooney has scored goals throughout his career but was most prolific between 2009-2013. Andrew Yates/AFP/Getty Images

But the statistical reality is that goals-per-game numbers have remained relatively unchanged throughout the Premier League's 25-year history. It was 2.8 last season, as it was between 2009 and 2013, and that's particularly interesting, with reference to Mourinho's comments because the earlier period was effectively Rooney's goalscoring peak.

Playing in a team based around him after the departure of Cristiano Ronaldo to Real Madrid, he scored 86 league goals in four seasons. As such, and despite what his former manager says, Rooney is not competing in a more defensive league these days; indeed, last year was only the fourth time in 25 seasons that the 2.8 mark has been reached.

The scoring rate has essentially always bounced around between 2.6 and 2.8 per game in the Premier League era, aside from a brief dip under the 2.5 mark just over a decade ago, not coincidentally during the period when Mourinho and Rafael Benitez, who inspired a more defensive shift in English football, were in charge of Chelsea and Liverpool respectively.

So the next question is this: If there aren't as many top-class defenders around, why hasn't the goals-per-game rate increased more significantly? There are two answers.

First, as mentioned, defenders operate differently and in a subtler way, often further from goal. Second, and more significantly, they're better protected. In the 1990s it was relatively rare for teams to field defined holding midfielders -- two box-to-box players was the standard approach -- which meant attackers could find space between the lines and defenders were dragged out of position and exposed more readily.

Today, there's an overwhelming emphasis upon getting men behind the ball and midfielders are instructed to shield the defence. West Brom manager Tony Pulis, for example, spends hours drilling his midfielders to shift laterally without leaving gaps between them; the type of drill that would have been reserved for defenders two decades ago. If you have a functioning, compact and defensive-minded team, your centre-backs often aren't stretched.

The consequence is that it's more difficult to find space in dangerous positions. Strikers aren't presented with regular point-blank chances and, therefore, simply being a good finisher is no longer enough. Instead there's more emphasis upon players who have a burst of acceleration over a couple of yards.

Without such a quality at the top level, players don't get the opportunity to showcase their close-range finishing. And it is essentially the same story as for out-and-out defenders: Forwards have become all-rounders, rather than specialists.

In a period of sweeping change for football, the main conclusion is that the average number of goals per game has changed very little. Compare the rate of scoring in football to the situation in England's traditional second sport, cricket, and there's a very different situation.

The MCC, responsible for the laws of cricket, recently published a document outlining its concern about "incontrovertible evidence that the balance between bat and ball has changed" and offered "some proposals as to how this balance might be redressed." Essentially, it has become easier to score runs, to the point that reform is needed.

Football doesn't have this problem -- there's no need to outline the increasing dominance of attack over defence, or vice-versa -- and that is remarkable: Football might have changed in many ways and is presented increasingly as pure televisual entertainment, but it isn't any easier, or harder, to score goals; they're simply scored in different ways, by different types of player.