SB, Can you give me one season where Daffy has scored 20 goals in the league?
You say about stats don't say anything, but you're misreading this stat SB. You can use a stat to predict future performance, but it is just that, a prediction and not a fact.
IE I pointed out 'arry's performance - he has a 50+% win average, one of the highest of all the managers. BUT I also pointed out that he hasn't been in charge for the same number of games as the greats. So, although a stat is an indication it is not a fact when used to project. Do you understand that? IT IS a fact when looking backwards, but not looking forwards. IE after something (season/match) ends you can quote stats of actual performance. BUT it would be stupid to project say, the first half of a game on the second - '...we had 20 shots and scored 3...so we'll end up with 40 shots and 6 goals...' type thing doesn't work. That is using a stat to predict. And as you know from the weather, predictions aren't always right are they?
I'm sorry about being stupid. I never actually studied statistics at school, so I'll leave it to you to guide me through the subtle intricacies of the 'science'.