Sentencing is a backward- and forward-looking enterprise. That is, sentencing is informed by an individual’s past conduct as well as by the criminal justice system’s prediction of the individual’s future criminal conduct. Increasingly, the criminal justice system is making these predictions on an actuarial basis, computing the individual’s risk of recidivism according to the rates of recidivism for people possessing the same group characteristics (e.g., race, sex, socio-economic status, education). The sentencing community is drawn to this statistical technique because it purportedly distinguishes with greater accuracy the high-risk from the low-risk, and thereby allows for a more efficient allocation of sentencing resources, reserving incarceration for the truly dangerous and saving the low-risk from needless penal attention. Despite these asserted benefits, risk-assessment tools are exogenous to the theories of punishment, the very foundation for sentencing in Anglo-American jurisprudence. This Article reviews the legality and propriety of actuarial predictive instruments, using these theories and governing constitutional and statutory law as the touchstone for this analysis. This Article then applies these normative and legal principles to seventeen major characteristics that may comprise an offender’s composite risk profile. It argues that risk-assessment instruments are problematic for three reasons: they include characteristics that are prohibited by constitutional and statutory law; subject the individual to punishment for characteristics over which the individual has no meaningful control; and presume that the individual is a static entity predisposed, if not predetermined, to recidivate, thereby undermining individual agency and betting against the individual’s ability to beat the odds.