Law360, New York (April 20, 2015, 9:30 AM EDT) -- Given the expense of post-grant proceedings at the Patent Trial and Appeal Board and the risk of estoppel, petitioners are understandably tempted to pursue more than one ground of unpatentability: If one ground does not succeed, they hope another will. Before the first petition was filed, however, the PTAB set tools in place to limit the number of grounds to minimize the risk of abuse. As PTAB post-grant dockets have swollen, the PTAB has expanded its use of one tool in particular — redundant grounds — as a docket-management device. Because a decision on whether to institute is essentially unreviewable on appeal, and the consequences of a ground denied on the basis of redundancy might not be apparent until late in the proceeding, redundancy poses a significant hazard for petitioners....