What does SBD stand for in World's Strongest Man?

Excuse me, but I'm curious to know what the acronym SBD stands for in the context of the World's Strongest Man competition? Is it related to a specific aspect of the competition, such as a scoring system, a category of events, or perhaps a particular prize that the winners receive? It seems intriguing, and I'd love to gain a clearer understanding of its meaning within this prestigious athletic event.