During the homolytic reactions of $CCl_4$ or $Cl_3CBr with ${eta}-halo^1$-styrenes,$eta$-haloradicals are key intermediates. They are to be stabilized via three pathways; $eta$-cleavage, halogen transfer and telomerization. The three reaction paths are delicately controlled by the energetics of their formation and stabilization. When the formation of a $eta$-haloradical is accompanied by considerable excess of energy from an exothermic reaction, $eta$ -cleavage is often dominant over the halogen transfer. On the other hand, if the radical forms via a reversible reaction, two processes become competitive. $eta$-Eliminated bromine atoms from ${eta}$ -bromoradicals generate $Br_2$ via $Cl_3CBr + {cdot}Br {leftrightarrow} Br_2 + {CCl_3}{cdot}{Br_2}$ may act as a better scavenger than Cl3CBr for the ${eta}$-bromoradicals. Different reactivities of chlorine, bromine and trichloromethyl radicals towards olefinic pi-bond are clarified in terms of the beat content of the addition reactions.