Why offside is the basic rule? This should start with the embryonic form of modern football, that is, the primitive football in the Middle Ages. Of course, this is not the shackles of ancient China, but the original football originated in England. The basic idea of primitive football is actually to transfer a theme from one village to another village's destination (such as church), and another village will stop another village. It can be seen from this source that the original football emphasizes the concept of "website". At the beginning, both sides had their own turf, and the game was more blocked than the other side, so football was called "mob football". Under this rule, the dividing line between the two sides has become the top priority of the whole movement because it represents the sphere of influence. You can call me an opportunist and send a group of people from my village to sneak into each other's websites. I will drive from one side of the party when I play. There are missed opportunities, but you should know that you are entering the other side's territory. In primitive times, there were no rules, no referees, serious competition, fists and fists, and the other side was cheap, so you planned to return completely ... So from the beginning, private "offside" was a very immoral behavior, which must be strictly prohibited.

1863, which is regarded as the first year of modern football. Britain established the first modern football association-Football Association, and formulated the first set of identical rules. The first set of "general rules" explicitly prohibits any form of touching the ball, but at the same time it also retains the offside rule of Cambridge Rules.

For the first time, the offside rule has changed like modern football. It was not until 1866 that the first pass was allowed, which made the prototype of the contemporary offside rule, limited between the ball and the opponent's bottom line. The number of defenders is one more than now. 187 1 The special position of the goalkeeper, usually the last defender, was introduced in the football match to determine the basic pattern of the offside rule we see today.