Methods of polymerizing at least one olefin include contacting the olefin with a catalyst comprising chromium and with a cocatalyst comprising a non-transition metal cyclopentadienyl (Cp) compound. The polymerization may be performed in the presence of hydrogen. Using the cocatalyst in conjunction with the catalyst increases several properties, such as the high load melt index (HLMI), the M.sub.W, and the M.sub.N, of the polymers produced by this polymerization method. Polymer compositions produced by such methods have various unique properties, including a PDI greater than about 30. Additional embodiments include articles of manufacture or end use articles formed from such polymer compositions.