Arena
Depending on the location of where the event is held, the size of the arena varies. In the standard size, according to Britannica, the arena is usually circular with a diameter of 6 meters. To keep both the birds and spectators safe, a barrier of some sort is usually built.
Match
Again, like the arena, the rules for the match usually depends on the region. To begin the match, under the control of the trainer, the birds would begin pecking at each other in a process called ‘billing’ (“Cockfighting | The Encyclopedia of Oklahoma History and Culture.”). The two birds would then be placed at a predetermined distance from each other, indicated by a line in the sand, and the match begins. For regions with tight regulations, the match would usually end once a bird draws first blood. Before regulations are put in place or in regions where it is done illegally, the match would normally continue until one of the two birds dies.
Results
As the sport evolved, what had begun as a pastime, introduced the thought of gambling. In those situations, the results of a match would entail a distribution of winnings to those who bet on the bird that lives. For the those who lost the bet, they lose any potential earnings. But worst of all, the owner of the bird that died, may have lost a close companion.