Some of the following is out of date, but not the repeated reference to 9 digit routing numbers. A bank's chances of having an 8 digit routing number are equal to yours of having a 8 digit SSN:
Appendix A to Part 229--Routing Number Guide to Next-Day Availability Checks and Local Checks
A. Each bank is assigned a routing number by an agent for the American Bankers Association. The routing number takes two forms: a fractional form and a nine–digit form. A paying bank generally is identified on the face of a check by its routing number in both the fractional form (which generally appears in the upper right–hand corner of the check) and the nine–digit form (which is printed in magnetic ink along the bottom of the check). Where a check is payable by one bank but payable through another bank, the routing number appearing on the check is that of the payable–through bank, not the payor bank.
B. The first four digits of the nine–digit routing number (and the denominator of the fractional routing number) form the ‘‘Federal Reserve routing symbol,’’ and the first two digits of the routing number identify the Federal Reserve District in which the bank is located. Thus, 01 will be the first two digits of the routing number of a bank in the First Federal Reserve District (Boston), and 12 will be the first two digits of the routing number of a bank in the Twelfth District (San Francisco). Adding 2 to the first digit denotes a thrift institution. Thus, 21 identifies a thrift in the First District, and 32 denotes a thrift in the Twelfth District.
If you want to go fast, go alone. If you want to go far, go together. African proverb