Fed.R.Civ.P. 50(a) permits a motion for judgment as a matter of law at any time before a case is submitted to the jury. Such a motion, however, "must specify the judgment sought and the law and facts that entitle the movant to judgment."15 If such a motion is not granted, the movant may renew it following a verdict.16 The fact that a post-verdict Rule 50 motion is regarded as nothing more than a renewal of any pre-verdict motion carries with it certain corollaries. Pertinent here is the proposition that a district court may not grant relief under Rule 50 after verdict except on specific grounds upon which the movant relied in a pre-verdict Rule 50 motion.17