Callaway Big Bertha (2002 Series). Harking back to the good ol' days of the revolutionary original Big Berthas, the Callaway Big Bertha 2002 Series feature a very deep cavity for incredible forgiveness and playability. The Callaway Big Bertha 2002 irons feature a wide constant-width sole design. Each iron in the set has a uniformly wide, rounded sole that positions weight low and deep throughout the set. The constant-width soles also help get shots airborne more easily - from the fairway, rough or sand. The wide, radiused sole design dramatically decreases digging on fat shots, and VFT (Variable Face Thickness) technology moves unneeded weight from the face, allowing for extreme perimeter weighting and maximum forgiveness.