Ok so I'm having this debate with a guy on soccer now vs then.

In this case then being more than 30 years ago.

He is convinced that play and players then were at a higher level than now.

And eventhough by simply using my eyes and observing I'm convinced that isn't true that's just something, due to how subjective it is, we'll ever even come close to agreeing on. He is simply not seeing what I am and vice versa.

Instead to move away from that I started using an argument based on very simple probability or just basic logic if you will.

Basically that in a sport which even in the last 10 years has seen a 20 million active player growth and who knows how many more millions in the last 30 years, that in such a sport there is a higher probability of good players than there were 30 years ago.

That the best of these players through advanced scouting compared to then are discovered earlier and then put through more advanced training than 30 years ago, I feel only helps my argument and makes more good players now, to whatever extent, even more probable.

Then he starts claiming that you can't use probability in this argument at all because it's not an experiment, but doesn't explain why exactly, instead opting for bringing forward examples of why the probability and the conclusions drawn from them is wrong. Examples I then find myself often criticizing for lack of sample size...

So with apologies in advance, if this is too simple and banal, I'd like to hear opinions on why you'd not be able to use probability in an argument like this and if you can to what extent it is valid.

Actually any input would be appreciated.

Here's a funny way to look at it. The average (or typical) soccer player of 30 years ago might very well be better than todays "average" player by virtue of the sports rapid growth in popularity. How can this be? If, in the past, only the best 1% of the athletic population played soccer but nowadays the best 5% of the athletic population plays soccer then statistically the average player in the old days would tend to be a better athlete than the average player of today. I can crank out some numbers to show this but you probably get the idea. I'm being a bit facetious but it is not a totally bogus argument.

You may really want to compare the very best player of the past with today's which is a whole different question.

Your argument is sound, but not irrefutable. In sports with objective comparisons, like track and field, it's clear that athletes are getting better. It's also clear that expanding potential talent pools helps.

However, it could be that the best potential soccer players are now drawn into other sports. It would not surprise me to learn that the best hurling team of 50 years ago is better than the best team today, as potential hurlers play soccer or basketball or lacrosse instead. That's probably not true of soccer.

Another consideration is intensity of training. Rising affluence often means that people have better opportunities than to train single-mindedly for athletic success. This factor is particularly true for sports that get people hurt, like boxing or strength positions in football. Again, I don't think this is a big factor in soccer yet, but it might start kicking in (pun intended) as countries like Brazil and China develop improved economies.