Method and system for tracking performance of a player

A system for tracking performance of a player, the system comprising:

• a rotating apparatus configured to be provided a rotation about the spin axis via a player, wherein the rotating apparatus comprises:
• a communication module;
• and
• an XYZ-magnetic field sensor configured to measure a plurality of magnetic field values as a function of time with the XYZ-magnetic field sensor when the rotating apparatus is rotating about the spin axis;
• and
• a processor communicably coupled to the rotating apparatus, wherein the processor configured to:
• determine a global direction of a magnetic field at a first court and compute first court specific data comprising a horizontal direction of a local magnetic field with respect to an x-axis of the global direction of the magnetic field and a vertical direction of the local magnetic field with respect to a local horizontal plane;
• determine that the rotating apparatus is in a ballistic trajectory and activate the XYZ magnetic field sensor;
• compute a magnetic field component of the magnetic field in a direction of a local body coordinate of the spin axis of the rotating apparatus from the measured plurality of magnetic field values;
• determine a direction of the spin axis using the computed magnetic field component of the magnetic field and the determined global direction of the magnetic field;
• determine a player specific data comprising an angle of the spin axis with respect to the horizontal ground plane and an angle of the shot direction with respect to the horizontal component of spin axis for the player;
• calibrate and store the first court specific data and the player specific data to track the performance of the player at the first court;
• determine a global direction of a second magnetic field at a second court and compute a second court specific data comprising a horizontal direction of a local magnetic field with respect to an x-axis of the global direction of the second magnetic field and a vertical direction of the local magnetic field with respect to a local horizontal plane;
• and
• calibrate and store the second court specific data and the stored player specific data to track the performance of the player at the second court.