The Pirates ZiPS projections for 2015 are available, and they're well worth checking out, because there are a number of likely members of the Pirates' roster whose lack of big-league track records make them tricky to project.
For example, it's unsurprising that ZiPS projects that the Pirates' two best position players will be Andrew McCutchen and Starling Marte, but it is a bit surprising to see Gregory Polanco at No. 3. (The top comps for McCutchen, Marte and Polanco are Duke Snider, Matt Kemp, and Milton Bradley, respectively, which sounds like some bitter Dodger fan's fever dream.) ZiPS thinks Neil Walker will have a pre-2014 Neil Walker season and that Josh Harrison will take a big step back while still being valuable overall. Jung-Ho Kang is projected to produce 1.5 WAR while striking out a ton. Prospect Willy Garcia's top comp is Rob Deer.
ZiPS projects that the Pirates' pitchers won't be as impressive, which shouldn't be a concern, I don't think -- advanced metrics didn't like the Bucs' pitchers much at all last year, and they kept runs off the board anyway, due to the Pirates' ground-ball-heavy approach. ZiPS does project good seasons from Francisco Liriano and Gerrit Cole, and it thinks Tyler Glasnow will be the Pirates' 10th most valuable pitcher, with a top comparable of ... A.J. Burnett. ZiPS sees a workmanlike fifth-starter type of season for Radhames Liz, and (unsurprisingly) seems to have no idea what to do with John Holdzkom. Cole's top comp is Kevin Millwood (which I can understand, although their stuff isn't remotely similar), Charlie Morton's is Omar Olivares and Casey Sadler's is Mike Lincoln.