Orbital period evolution versus companion mass of the simulated binaries for β = 0.7 and with an initial NS of mass 1.3 M_⊙ and f_pulsar values of 0.0 (top left), 0.05 (top right), 0.1 (bottom left), and 0.5 (bottom right). The term M_c is the mass of the companion to the NS, and P_orb is the orbital period. We also compare our tracks to estimated M_c, min and observed P_orb for spiders (Section 2.4). The initial binaries have a MS star (range of 1.0 to 4.5 M_⊙) and initial periods of 0.6 to 4.0 d.