In England and I gather in all the common law jurisdictions, deciding whether or not to follow a prec is not at the discretion of the court. The doctrine of prec is closely linked to the hierarchy of the Courts whereby certain courts bind the lower courts but not themselves, some courts bind themselves. (Sorry I can't remember which do what exactly). For ex. until recently, it was believed the House of Lords bound itself although legal history was made recently (Pinochet case) when the HoL did not follow itself when a differently composed HoL made a slightly different decision in that case. So sometimes in a case, a judge will say that he is bound to follow prec and has to make a certain decision (throwing hints that they should appeal and go higher to a court able to overturn prec). Or, sometimes, they "distinguish"; meaning: this case is sufficiently different from prec on its facts for us not to follow prec.