Past experience and all data now useless!!
What bugs me about this is that I have been trying to build up a great database (6000) loans and had done many analysis - eg analyse all loans for the year 2006 (2260 loans) by grades (A1 to F5) for defaults, interest received, %age repaid, etc etc. The objective was to determine, as time goes by, which grades are the best to invest in without diluting the results with new loans.
With this change, all those data and knowledge are rather useless. As Harmoney states " This means that a borrower that was a C3 on the old scorecard is unlikely to be a C3 on the new scorecard"