The client is looking for a best practices solution for credit card retry setting.
The optimal setting is best worked out with the client's Charge Vendor (i.e. Sage). In version 5.0.19 of TA there is a feature the client may find helpful:
Codes to change to a CK Pledge TA references this system preference (located under Procedures/Charge Processing, in the Operation Preferences section) when a payment is declined during Charge Processing. Set this preference to one or more rejection codes that indicate a charge pledge should be changed to a CK pledge when a payment is declined. When a payment is declined with any of the specified rejection codes, Charge Processing will change the pledge to a CK pledge regardless of the Maximum Number of Charge Rejections system preference (see "Maximum Number of Charge Rejections)