The points total takes into account the best 18 tournaments out of the last 26 tournaments played (exception: points from Grand Slam, Elite 1000 tournaments and MTL Finals played are automatically taken into account).
Defending points: it displays eather your 19nd best tournament result points or your previous year result if this tournament was one of your 18 best results in 26 weeks rolling.
These datas can be found in the "ranking" tab on your player's profile.
The same rules are applied for the other players on the pro circuit.
Important note:
The Tennis Manager "Tennis World" composed by the other players on the circuit, the tournaments and results are saved on the user's device (your device!). this means if you change your device or if you clean the data of Tennis Manager app, you will see some issues with points and rankings. Please play 26 new weeks/tournaments and all will be return to normal.