Multi-layer golf ball

A multi-layer golf ball comprising:

• a single-piece spherical core defining an innermost portion of the golf ball, the core being formed, in whole or in part, from an ionomeric material and having a 10-130 kg compression deformation of between about 3.5 and 5.5 mm, the core having an outer surface that includes:
• a plurality of polygonal land portions aligned on a common sphere datum;
• and
• a plurality of grooves separating the polygonal land portions and extending radially inward from the common sphere datum, each of the grooves having a groove depth in a radial direction relative to the common sphere datum of about 0.2 to 0.6 mm;
• an intermediate layer surrounding the core and having a radially inward surface bonded to the outer surface of the core, the radially inward surface including a plurality of protrusions projecting into and filling the grooves of the core, the intermediate layer being formed, in whole or in part, from a rubber material and having a radial thickness of between about 4.0 and 9.0 mm, the intermediate layer and the core defining an intermediate ball;
• and
• a cover layer surrounding the intermediate layer and defining an outermost surface of the multi-layer golf ball,
• wherein the intermediate ball has a 10-130 kg compression deformation of between about 2.7 and 5.5 mm, the 10-130 kg compression deformation of the intermediate ball being less than the 10-130 kg compression deformation of the core.