Multi-piece solid golf ball

A multi-piece solid golf ball comprising a core, an envelope layer, an intermediate layer and a cover,

• wherein the core, envelope layer, intermediate layer and cover have respective surface hardnesses which satisfy the relationship:
• core surface hardness>envelope layer surface hardness<intermediate layer surface hardness<cover surface hardness;
• the surface hardness of the core and the surface hardness of the envelope layer, expressed in terms of Shore D hardness, satisfy the relationship:
• −14≦(envelope layer surface hardness−core surface hardness)≦−5;
• the surface hardness of the intermediate layer and the surface hardness of the cover, expressed in terms of Shore D hardness, satisfy the relationship:
• 5≦(cover surface hardness−intermediate layer surface hardness)≦15;
• the ball and a sphere composed of the core covered peripherally by the envelope layer and the intermediate layer (intermediate layer-encased sphere) have respective initial velocities (m/s) which satisfy the relationship:
• −1.0 m/s≦(ball initial velocity−intermediate layer-encased sphere initial velocity)≦0 m/s;
• the intermediate layer-encased sphere and a sphere composed of the core covered peripherally by the envelope layer (envelope layer-encased sphere) have respective initial velocities (m/s) which satisfy the relationship:
• −0.2 m/s≦(intermediate layer-encased sphere initial velocity−envelope layer-encased sphere initial velocity);
• and
• the ball satisfies the relationship:
• 0.86≦A/B≦0.98,
• where A is the deflection (mm) of the ball when compressed under a final load of 1,275 N (130 kgf) from an initial load of 98 N (10 kgf) and B is the deflection (mm) of the intermediate layer-encased sphere when compressed under a final load of 1,275 N (130 kgf) from an initial load of 98 N (10 kgf), and wherein the surface hardness of the envelope layer and the surface hardness of the intermediate layer, expressed in terms of Shore D hardness, satisfy the relationship:
• 20≦(intermediate layer surface hardness−envelope layer surface hardness)≦30.