An olefin polymerization catalyst system comprising: a first olefin polymerization procatalyst, a second olefin polymerization procatalyst, and a chain shuttling agent, wherein the second olefin polymerization procatalyst comprises a metal-ligand complex of Formula: wherein M is titanium, zirconium, or hafnium; wherein each Z1 is independently a monodentate or polydentate ligand that is neutral, monoanionic, or dianionic, wherein nn is an integer, and wherein Z1 and nn are chosen in such a way that the metal-ligand complex of Formula is overall neutral; wherein each Q 1 and Q 10 independently is selected from the group consisting of (C 6 -C 40)aryl, substituted (C 6 -C 40)aryl, (C 3 -C 40)heteroaryl, and substituted (C 3 -C 40)heteroaryl; wherein each Q 2, Q 3, Q 4, Q 7, Q 8, and Q 9 independently is selected from a group consisting of hydrogen, (C 1 -C 40)hydrocarbyl, substituted (C 1 -C 40)hydrocarbyl, (C 1 -C 40)heterohydrocarbyl, substituted (C 1 -C 40)heterohydrocarbyl, halogen, and nitro (NO 2); wherein each Q 5 and Q 6 independently is selected from the group consisting of a (C 1 -C 40)alkyl, substituted (C 1 -C 40)alkyl, and [(Si) 1 -(C+Si) 40] substituted organosilyl; wherein each N independently is nitrogen; optionally, two or more of the Q 1-5 groups can combine together to form a ring structure, with such ring structure having from 5 to 16 atoms in the ring excluding any hydrogen atoms; and optionally, two or more of the Q 6-10 groups can combine together to form a ring structure, with such ring structure having from 5 to 16 atoms in the ring excluding any hydrogen atoms; wherein the first olefin polymerization procatalyst comprises a metal-ligand complex of the formula: wherein: M is zirconium or hafnium; R 20 independently at each occurrence is a divalent aromatic or inertly substituted aromatic group containing from 5 to 20 atoms not counting hydrogen; T 3 is a divalent hydrocarbon or silane group having from 3 to 20 atoms not counting hydrogen, or an inertly substituted derivative thereof; and R D independently at each occurrence is a monovalent ligand group of from 1 to 20 atoms, not counting hydrogen, or two R D groups together are a divalent ligand group of from 1 to 20 atoms, not counting hydrogen. a first olefin polymerization procatalyst, a second olefin polymerization procatalyst, and a chain shuttling agent, wherein M is titanium, zirconium, or hafnium; wherein each Z1 is independently a monodentate or polydentate ligand that is neutral, monoanionic, or dianionic, wherein nn is an integer, and wherein Z1 and nn are chosen in such a way that the metal-ligand complex of Formula is overall neutral; wherein each Q 1 and Q 10 independently is selected from the group consisting of (C 6 -C 40)aryl, substituted (C 6 -C 40)aryl, (C 3 -C 40)heteroaryl, and substituted (C 3 -C 40)heteroaryl; wherein each Q 2, Q 3, Q 4, Q 7, Q 8, and Q 9 independently is selected from a group consisting of hydrogen, (C 1 -C 40)hydrocarbyl, substituted (C 1 -C 40)hydrocarbyl, (C 1 -C 40)heterohydrocarbyl, substituted (C 1 -C 40)heterohydrocarbyl, halogen, and nitro (NO 2); wherein each Q 5 and Q 6 independently is selected from the group consisting of a (C 1 -C 40)alkyl, substituted (C 1 -C 40)alkyl, and [(Si) 1 -(C+Si) 40] substituted organosilyl; wherein each N independently is nitrogen; optionally, two or more of the Q 1-5 groups can combine together to form a ring structure, with such ring structure having from 5 to 16 atoms in the ring excluding any hydrogen atoms; and optionally, two or more of the Q 6-10 groups can combine together to form a ring structure, with such ring structure having from 5 to 16 atoms in the ring excluding any hydrogen atoms; M is zirconium or hafnium; R 20 independently at each occurrence is a divalent aromatic or inertly substituted aromatic group containing from 5 to 20 atoms not counting hydrogen; T 3 is a divalent hydrocarbon or silane group having from 3 to 20 atoms not counting hydrogen, or an inertly substituted derivative thereof; and R D independently at each occurrence is a monovalent ligand group of from 1 to 20 atoms, not counting hydrogen, or two R D groups together are a divalent ligand group of from 1 to 20 atoms, not counting hydrogen.