ABAQUS (6.8, 6.9 EF) - Effect of the number of back stresses

Since ABAQUS 6.8, a new feature has been added to the combined hardening material input.

Let's assume a combined Kinematic and Isotropic hardening case, such as those happen in metals.

"Half cycle" uni-axial test results has been utilized to model the yield stress-plastic strain behavior as well as the Kinematic behavior of the metals.

In the same user interface,  there is an option to choose the number of back stresses.

Is the number of 1 back stress is equivalen to the case of linear kinematic hardening (Ziegler's)?

Similarly, does it mean higher values for the number of back stresses trigger nonlinear kinematic hardening in the ABAQUS model? If so, does it mean using higher values for the "number of back stresses" option when half-cycle input data has been used, more closely predict the kinematic hardening behaviour of metals/models?

Thank you,

Ron.