Negative hardness gradient cores made of polyalkenamer rubber for golf balls

A golf ball, comprising:

• a dual-core comprising an inner core and outer core layer, wherein the outer core layer surrounds the inner core, the inner core having a first outer surface and a geometric center, the inner core being formed from a first rubber composition, the first rubber composition comprising a cycloalkene rubber having a trans-content of 55% or greater and a melting point of 30° C. or greater in an amount of at least 50 weight percent, wherein the first outer surface and geometric center each has a hardness, the hardness of the first outer surface being the same or less than the hardness of the geometric center to define a first zero or negative hardness gradient;
• the outer core layer having a second outer surface and an inner surface, the outer core layer being formed from a second rubber composition, wherein the second outer surface and inner surface each has a hardness, the hardness of the second outer surface being in the range of 50 to 85 Shore C units and the hardness of the inner surface being in the range of 51 to 86 Shore C units, the hardness of the second outer surface being the same or less than the hardness of the inner surface to define a second zero or negative hardness gradient;
• and
• a cover layer surrounding the outer core layer.