Embodiments of methods of producing 1,4-polybutadiene comprise polymerizing a solution comprising conjugated diene monomer and organic solvent to yield 1,4-polybutadiene having a cis content of between about 92% to about 98%, a vinyl content of about 1% to about 5%, a trans content of about 1 to about 3%, a molecular weight distribution (MWD) of about 3 to about 5, and a Mooney viscosity (ML1+4) at 100° C. of less than 60. The polymerization achieves over an 80% conversion of the conjugated diene monomer when catalyzed with a catalyst comprising at least one nickel compound, at least one aluminum activator compound, and a mixture of BF3.hexanol and BF3.H2O. For the catalyst, the molar ratio of Ni/H2O is from about 0.05 to about 20 and the molar ratio of BF3/H2O is from about 1.8 to about 500.