If you say that Leno is better because of 'sample size', you admit that you actually have no idea and that you are incapable of judging the player over those minutes. Real life scouts could judge ability in under 10 games.

I don't need 10 games to tell that he commands his box, takes crosses or has good distribution. You need confidence in what your eyes can see.

Someone told me that Greenwood's 10 non pen league goals can't be expected again because of a small sample size. You can tell why he scores so many if you watch him shoot once. Nobody can fluke that technique + power. 'Sample size' typically means out of your depth.