The freedom of a court, state or federal, to define the limits of ad- herence to precedent has been sanctioned by the Supreme Court in both civil' and criminal cases. Accordingly, any decision can be made to apply to future cases or relate back to all past cases. In no other area of the law is such a decision more important than in the field of criminal procedure where the freedom of a convicted man can rest upon a decision to apply a new "rule" retroactively or prospectively. It is not surprising, therefore, that the majority of retroactivity cases involve the rights of a criminal defendant.