According to Article 177 of the Criminal Law of People's Republic of China (PRC), the crime of obstructing credit card management refers to the act of violating credit card management regulations and obstructing credit card management. Specifically, it includes the following behaviors:

1. Knowingly holding and transporting a forged credit card;

2. Holding and transporting a large number of credit cards knowing that they are invalid;

3. Illegally holding a large number of other people's credit cards;

4. Use false identification to defraud credit cards;

5. Selling, buying or providing others with forged credit cards or obtaining credit cards by fraudulent means.

For the number of convictions for the crime of obstructing credit card management, according to the provisions of the Interpretation of the Supreme People's Court and the Supreme People's Procuratorate on Several Issues Concerning the Specific Application of Laws in Handling Criminal Cases of Impairment of Credit Card Management, those who knowingly hold more than 10 credit cards shall be deemed as "a large number"; Illegal possession of more than 5 credit cards and less than 50 credit cards shall be deemed as "a large number".

To sum up, the number of convictions for the crime of obstructing credit card management varies according to the type of behavior and the circumstances, and needs to be judged according to the case.