The guidelines fail to provide a rational and coherent sentencing system because they do not provide sentences that achieve the statutory purposes of sentencing. By basing the guidelines on the mathematical averages of past sentences, the guidelines incorporate inaccurate measures of past practice to determine future practice. The guidelines fail to rank offenses systematically according to seriousness and do not address the problems of fragmented and overlapping offenses. The guidelines invite disparity due to their skeletal rather than comprehensive character. Disparity is also fostered by vague and ambiguous standards and provision for extensive departures from the guidelines without the guidance of a clear sentencing policy. The guidelines impede their future refinement by relying on the courts to develop the guidelines and by not permitting adequate appellate review. The flaws in the guidelines have not been exposed due to the lack of an impact assessment and the absence of informed deliberation and analysis. Congress should disapprove the guidelines and direct the commission to restart its work under the mandate of establishing rationality and consistency in criminal sentencing.