For example, modern sumo you have a prearranged position to start from. This is because of the ring and the rules designed around it, which came at a later date. Before the ring, before the advent the ring and rules, sumo started by standing or a half crouch. The position that the wrestlers would take today was far different than what was done in the past. The rule to push the opponent out of the ring created an atmosphere where smaller opponents would take a modern, lower crouch; the idea of thrusting forward as strongly as possible dominated the way sumo was performed. The notion of a mutual start was also not done, as this came about through the addition of rules through time. Before the addition of the ring there were two overall types of sumo practice. The first is known as "Bujinzumo" [武人相撲] and Kanjinzumo [勧進相撲].
Kanjinzumo was mainly practiced at ceremonies and festivals, shrines, temples, consecrated areas and events to bring good fortune. It was attached to big events or local gatherings, and had an overall “local fun” feel about it. It was a type of recreational entertainment and a local sport for the youth and adults, which was used as a cultural tool as much as anything else that accompanies festivities. Shrines and consecrated areas used it as a sort of devotion to higher powers, usually along with religious rights and purification ceremonies.
Bujinzumo, on the other hand, was auxiliary to weapons and war fighting tactics. It was something done with the use of weapons and without the confines of rules. It was violent, involved striking and kicking, and whatever else could be mustered. On the other hand, sumo was also something practiced at the campsite for health and recreation; which then would be translated into serious action while fighting in a war theater.
Before rules prohibited it, there were various postures one could take. Illustrations from the era show them in detail, with descriptions of how there were used. The most simple forms are called "Inemuri no so" (Sleeping stance) [居眠相], "Kiso no teai" [奇相の手合い] or "Mukei no teai" [無形の手合い] (irregular or formless stance), "Inyo no teai" (Ying/Yang stance) [陰陽の手合い], "Jodan no teai" (upper stance) [上段の手合い], "Chudan no teai" (middle stance) [中段の手合い], and "Gedan no teai" (lower stance) [下段の手合い]. These stances were used at the beginning of the matches but are now relegated until after the match begins. However they show that sumo in the original form was extremely pliable to the situation as rules did not dominate the context of a match. That being said it was a battlefield art as well as a celebratory event, having different functions according to need.