My best friend has dumped her old boy friend and has a new one, and he has turned out to be an interesting guy to share some beers with him as he's a coach in Antiguoko and knew well Alonso when he was 13-17.
Believe it or not, Alonso saw many games from the bench. His brother was better at the time, because he was stronger. At that age (the coach said) they all saw Alonso "had something" special, but bigger boys than him outplayed him due to that strenght. Xabi was quite a shy guy at the time, and somehow he was always under the shadow of his brother. Now he's a world class player and his brother hardly can be considered a primera player.
Fortunately enough a summer everythin changed, Xabi's body changed and he started to be the man we all know. For when I saw him the first time seriously (loan spell in Eibar) I already knew that guy was the best product of our youth system in 20 years.
But it makes me think how many talented players do not reach highest levels due to they don't get the required body soon enough, I see too many big boys playing in the best youth teams just because of that... Reaching the hiighest level can certainly be a matter of luck or a matter that a certain coach is spot on with a player.