What should be the focus when calculating the line pull needed for a snatch block?

The focus when calculating the line pull needed for a snatch block should encompass the load weight multiplied by the coefficient of friction. This calculation is crucial because it takes into account not only the weight of the load being lifted but also the resistive forces that may be at play due to friction between the load and any surfaces, or within the rigging system itself. The coefficient of friction can vary based on the materials involved and the conditions, such as whether the surfaces are wet or dry, smooth or rough.

Utilizing just the weight of the load without accounting for these frictional forces would lead to an inadequate assessment of the necessary line pull, as the actual force required to move the load will be greater when friction is a factor. Similarly, while environmental factors may certainly influence the overall rigging situation, they are typically encapsulated in the coefficient of friction, making this choice the most comprehensive and therefore the best focus for calculating line pull.