Maybe you don't know how a subduction zone works, where there can either be slip along the plate boundary fault or faulting within the subducting slab. Nor the difference between a normal and a thrust earthquake.

Mechanically, normal and thrust event distort the Earth in opposite senses - the former laterally stretching the Earth, and the latter laterally compressing the Earth.

Just in case you're looking at how the shadow of a stick moves on a wall for your prediction method - the two earthquakes we're discussing here should appear in an opposite way, in the unlikely event they appear at all.