Is it a tradition for the best player on a team to wear the number 10? If so who, what, where, when started this tradition? Do all clubs do this? What does it mean to be a "number 10" or a number "nine player"?
To begin with, the number 10 is not necessarily the best player on the team. Before the players got to keep their number during the entire season and they started to assign higher numbers (20 and up), soccer players were assigned a number before every game. Surely the usual starters kept their number more often than others. The numbering was by position, somewhat like in the baseball scorecard the 3rd baseman is #5 so the keeper was #1. Anyway. #1 = Keeper #2 = Right back (used to man mark the opponent supporting forward) #3 = Left back (used to mark the opponent right winger) #4 or #6 = Sweeper (manning the defense and supporting all the markers) #5 = Stopper or Center D. (used to mark the opponent main forward, the centravanti) #4 or #6 = Defensive mid or Mediano (Holding mid, used to mark the opponent fantasista) #7 = Right winger (used to be a forward, evolved in a midfielder) #8 = Midfielder or mezzala (used to be the main distributor, the "regista" of the team... think Falcao) #9 = Main forward or centravanti (Batistuta, Luca Toni, Gerd Muller, Van Basten, etc...) #10 = Attacking midfielder (evolved more in a fantasista or pure creative touch role) #11 = Second forward or left winger (think Gigi Riva or Bettega) #12 = Reserve keeper #13 = Reserve defender #14 = Reserve mid (or reserve forward) That is up to about 25 years ago... than the bench changed and the numbers started to get crazy!
A long time ago in a galaxy far, far away teams played with five strikers. Like this: 11--10--9--8--7 Behind that three midfielders: 6--5--4 And two defenders: 3--2 In a 4-3-3 the '8' and '10' become midfielders, and the '4' and '5' become defenders. Since in Holland the most used line-up is a 4-3-3 the '5' became the left fullback and the '3' became the sweeper. Like this: 11--9--7 10--8 6 5--4--3--2
In Argentina the number 10 and 9 refer to specific positions, whether the player wears that number or not. The main offensive creator (which Italians might call 'fantasista') has been called the number 10, Kempes, Maradona, Ortega, Riquelme are examples of a number 10. The penalty area centerforward and finishing specialist is called the number 9, whether he wears the number or not. Examples of a number 9 would be Luque, Batistuta, Crespo. For example, we might say, 'If Riquelme gets hurt, Aimar can replace him at the 10.' (Meaning he would take on the role, even though he wouldn't be wearing that number.)
In Italy, the system played in the late 60s to the 70s which I was referring above looked like this for numbers with th #6 being a drop back sweeper. Similar to the Dutch system you posted. 11--9--7 10--8 4 3--5--2 6 You can see how the #7 progressively dropped to the midfield line to create the formation that won the WC in 1982 (Bruno Conti was the 7) 11 (Graziani)--9 (Rossi) 10 (Antognoni)--8 (Tardelli)--7 (Conti) 4 (Oriali) 3 (Cabrini)--5 (Collovati)--3 (Gentile) 6 (Scirea)
In Argentina it was a bit different. In the days of the 4-2-4 or 4-3-3: ...........1 ..3....2......6....4 .......5.....8 .........10 ..7.....9.....11 1 is goalie 2 and 6 are central defenders 3 and 4 are laterals 5 is more defensive mid 8 is more two way area to area player 10 is offensive creator 9 is centerforward 7 and 11 are wings. Nowadays the 7 is another mid, and the 11 is either wide or a withdrawn striker. The 3 and 4 can be wingbacks. But they don't really use the fixed numbers anymore.
In addition to that , In some countries like Brazil when the numbers are assigned, it's a big deal because it gives an indication of who the prefered starting 11 are. For example if we where to hear that Aimar was to wear the number 10 it would be a big deal ,not only because of history ,but also because he would be perceived differently. If Adriano (7) where to wear the Number 9 , Ronaldo would be seen as if he got demoted .
in england over the past 30 years it's usually been: .........................1 ................2.....5....4.....3.........defence ...............7......6....8.....11.......midfield ......................10...9...............forwards obviously it varies, but that was the most common place for players wearing a certain number. i've noticed that on the continent and in argentina, number 10 is often the playmaker/forward, like maradona. this is also quite common in england (eg bergkamp). the other difference is that in england number 11 is nearly always a midfielder or winger, not a forward. but at the end of the day - who really cares
10 ussually goes to the attacking playmaker. However, two of the best attacking playmakers of their generation play with number 5 for their club. Zidane & Rivaldo. (I think the thought behind that is they are supposed to be the symbolic "centre" of the team. Either that, or it was the only number available at the time for both those players and its one big coincidence )
A funny thing about this happened when Ronaldo arrived to Inter. He, of course, wanted the 9, and because he was the new star, the 9 went to him. The thing is that Zamorano used to have that shirt, and as they make him give it away to Ronaldo, he choosed the 18, but he added a little "plus symbol" between the numbers in his shirt, so he really used the "1+8" and, as you know, 1+8=9 (and as you can see, even if he couldn't use the shirt he wanted, they let him be the captain sometimes)
In Spain the 4-4-2 used to be a bit different: ....9 .............7 .......10 11...........8 ........6 3...4....5...2 The 5 is usually a defender, unlike in Argentina where it's always the deep lying midfielder, and the 7 is usually reserved for the support striker.