Exhibit 10.23

                                     FOURTH
                               CONTRACT EXTENSION



Fair,  Isaac and Company,  Inc.  and William R. Fair hereby  extend the contract
between  them for Mr.  Fair's  services  as a  consultant  to the Company for an
additional  year,  that is from April 1, 1995 through March 31, 1996,  all other
terms and conditions remaining the same as in the original contract.

In witness whereof, the parties have executed this contract extension as of this
7th day of April, 1995.






Fair, Isaac and Company, Incorporated





By:  Larry E. Rosenberger                              William R. Fair
     -------------------------------------             -----------------------
           Larry E. Rosenberger                           William R. Fair
           President and CEO