Suppose if you will that you are in a Race-notice Jurisdiction and the following occurs:
O conveys Blackacre to A, who does not record the deed from O to A. O conveys Blackacre to B, who has no knowledge of the transaction between O and A. B does not record. Who owns Blackacre?
Since neither recorded I'm not sure if A would win since he was first in time and would win a common law, or if B would win because she was a SBP without notice. I'm guessing A wins under common law.