In this sport the goal is to drug a rock to complete as many plaza (the distance between the two ends of the square) as possible within a given space of time. The rock is called probarri and it can be drugged by humans (in a group or alone) or by animals (oxens, horses, donkeys…). In this way, there are human tests or wagers, oxen wagers, horse wagers and donkey wagers.
Normaly this kind of wagers are plaied in pebbled squares called probatoki where the drugging of the rock is easier.
Oxen wager’s origin is supposed to be in quarry works. The rocks that were broken because of an explosion used to be polished and carried by the oxens.
Although firstly the events were wagers, nowadays generally they are competitions.
The oxens that are trained for competitions, appart from doing their daily works in the farm, have to walk for around 5 km in the mountains everyday and occasionally they are taken to the nearest square in order to mantain their dragging habit. We can still find competition rocks in some village squares of the Basque Country.
The rock is generally rectangular, a little bit more tight in the front. It also has a hole to attach the chain. The weight varies from village to village and may be between 1.500-4.000 kg. For example the rocks in Gernika and Mungia weight 4.500 kg. Or it can also be heavier as the one in the village of Berriatua, which is a 5.250 kg rock.
The rocks for competitions are usually smaller than the ones for wagers in order to have a more entertaining and enjoyable spectacle.