Determining chirality based on Fischer Projections is effectively the same as the standard method. The primary difference is the benefit that Fischer Projections provide in depicting the orientation of substituents with the vertical and horizontal lines. Considering that orientation of these molecules is already known, it may be properly depicted with wedges and dashes if needed. After this, the priority of each of the groups bonded to the carbon are ranked and the chirality is determined in the standard fashion. While there is no significant difference in the actual process of determining chirality, Fischer Projections allow one to better visualize where substituents are in space making it convenient to assign S or R chirality based on this model. In certain cases, it can be helpful to draw a Fischer Projection from a larger molecule to visualize and determine the chirality of a specific carbon.