Put another way, when the patentability of claims challenged is determined on a per petition basis, in nine percent of petitions all claims were deemed patentable, in 15 percent of petitions some claims were deemed unpatentable, and in 73 percent of petitions all of the claims were deemed unpatentable. It therefore appears that once the PTAB( Patent Trial and Appeal board ) gets involved, the chances that the challenged claims will be struck down rises precipitously.