| abstract |
A golf ball includes a core and a cover. The core has an outer surface, a geometric center, and a soft transition region adjacent to the outer surface. The soft transition region has a thickness of 4 mm or less, includes about 10 to 30% trans-polybutadiene isomer, and has a positive hardness gradient of about 10 Shore C or less. The cover layer has a hardness of about 50 Shore M or greater. The core has a positive hardness gradient of about 10 to 42 Shore C. A secondary gradient quotient, GQ′, from about 2.2 to 9.5, GQ′ being defined by the equation: n n n n n n n G n ′ n n + n T n n n 10 n × n COR n n n n n n where G′ is the core positive hardness gradient in Shore C, T is the percent of trans-polybutadiene isomer at the core outer surface, and COR is the coefficient of restitution of the core measured at an incoming velocity of 125 ft/s. |