This imaginary fulcrum point enables one to provision the power between the upper and the lower hand instinctively. Furthermore, while operating a lever, a Spey Caster also applies a ‘translation’ at the fulcrum point (see diagram 2). As with any good fly casting, late rotation or in Spey casting, late fulcrum is desirable to produce an effective fly cast. The amount of translation of the fulcrum point and the amount of lever push depends on the type of lines we cast. A longer line (long belly) requires longer translation and a longer pull of the lower handle - shorter line (Scandi, Skagit), shorter translation and shorter, more compact pull of the lower handle.
The mark of a good spey caster is to have the ability to instinctively and fluidly
manipulate the location of this fulcrum point during the whole casting process.