Abstract: A putting training device having the same size and feel of a standard golf ball yet adapted to exaggeratedly deviate from an expected line of action when mishit relative to a predefined line of action. The putting training device may have one or more inner cavities wherein an inner spherical object rolls along a tracked, concentric first curvature when the putting training device is struck with a putter accurately along the predefined line of action, and wherein the inner spherical object moves to a side portion of the one or more cavities upon the putting training device being mishit, resulting in the exaggerated deviation that affords the user a visual feedback they can learn from and recalibrate their future putts to.