The Tenth Circuit recently reminded us that, before a court may treat a prior conviction as an ACCA predicate, "we must be 'certain' that the violent-felony moniker 'necessarily' applies." United States v. Degeare, 884 F.3d 1241, 1244 (10th Cir. 2018). How certain? The Court does not say (neither party briefed the issue), but "at least more certain than not" (emphasis the 10th's). Id. at 1248 n.1.
If you have a close case involving a prior conviction under a statute that does not clearly and necessarily qualify as an enhancement predicate, invoke this certainty principle as a reason your client's sentence should not be enhanced.