A picture to illustrate the effect of the cylinder centerline offset in relation to the crankshaft center. TDC is when the crank center, the crank throw/rod big end, and the rod /wrist pin are all aligned. With no off set all are parallel with the cylinder centerline. With an offset the crank has to rotate to bring the three points in line and put the piston at TDC; and now the rod is at an angle in relation to the cylinder centerline.