The first ZiPS breakdown that occurred here at Rum Bunter, focused on the starting rotation. The Pirates currently have four locks, with Gerrit Cole, Jameson Taillon, Ivan Nova, and Chad Kuhl having themselves a spot.
ZiPS has Cole with a 86 ERA-, Taillon at 92, Nova 100, and Kuhl being the worst of the bunch at 113. For Kuhl, that is essentially a Jeff Locke projection, as Locke posted a 111 ERA- and a 119 ERA- in 2014 and 2015. This leaves the Pirates with a spot in the rotation, and potentially two spots down the road if Kuhl performs to his projection, or even worse.