The memory is still fresh in our minds of seeing the Czech Republic squad for Euro 96. The first-choice centre-backs, Jan Suchoparek and Miroslav Kadlec, were numbers 3 and 5 respectively while Pavel Nedved, then considered a left-back, was 4. It was a head-scratcher for those familiar with the Western European convention of having 2 and 3 as the full-backs. For the origins, we have to go back to the great Hungary team of the 1950s, under the management of Gusztav Sebes.
When 2-3-5 became the W-M, the Hungarians decided to sort out the numbering too. Jonathan Wilson in Inverting The Pyramid quotes Kenneth Wolstenholme’s commentary from the famous England-Hungary game of 1953:
“You might be mystified by some of the Hungarian numbers. The reason is they number the players rather logically, with the centre-half as 3 and the backs 2 and 4.”
By ’53, though, Sebes had evolved the W-M to more a W-W, playing number 9 Nandor Hidegkuti as an attacking midfielder so that the opposition’s centre-half, used to picking up 9, would be drawn out of position. If the ‘logic’ used to re-number the defence had been followed, Hidegkuti would have been 8 with the strikers 10 and 11, but this didn’t happen so the Magical Magyars looked like this:
When 4-4-2 was adopted, generally the number 5 dropped back alongside 3 and, as Hungary had been such a power, a lot of the other countries in Eastern Europe took their cues from them.
Squad Numbers Blog 