It's not easy projecting how a player will perform in a particular season. You can try it the more traditional way, and simply look at the player's final results the year prior and adjust them slightly based on factors such as age or career norms. Or you could go the more analytical route, and use formulas and trends that are not necessarily reflected on the player's basic statsheet. Either way, even with hours and hours of effort poured into trying to generate the proper expectations to set for a player they often prove to be wildly inaccurate. And on the surface, it seems that the Yankees' pitching staff is loaded with pitchers whose projections are even more guesswork than the norm.
I won't even attempt to get into the projections of Masahiro Tanaka and Michael Pineda, who have not thrown a pitch in MLB in 2012 or 2013. I'll even opt to avoid CC Sabathia, whose one bad season and dropping velocity deserve its own post for trying to figure out what he'll bring to the table. I'm most intrigued by Ivan Nova and Hiroki Kuroda, who each spent a period of 2013 as the Yankees best starting pitcher. Kuroda was lights-out and a Cy Young candidate all the way into August and Nova returned from a stint in the minors looking like a brand new pitcher. But they both had extended stretches during the season where they were incredibly hittable pitchers.
(April-July) 2.38 ERA, .609 OPS
(August-September) 5.40 ERA, .837 OPS
(April-May) 5.36 ERA, .821 OPS
(June-September) 2.66 ERA, .643 OPS
So that works out to a little over a full season of Cy Young-level performance between the two. If it's unrealistic to expect Nova and Kuroda to replicate their best stretches of last season, the Yankees would at least prefer that they bring a little more consistency to their performances this season.
When looking at their ZIPS, Steamer and Oliver projections, unsurprisingly it appears there wasn't that much consideration for the good or bad stretches that Nova and Kuroda had. Much more weight was put into their careers and full season performance, which generally speaking, is the more statistically sound methodology. Both players are projected to have an ERA in the high 3's to low 4's, with Kuroda projected for over 3 fWAR and Nova between 2-3. The projections in all three systems are pretty bearish and expect campaigns inferior to their 2013 seasons, but considering Nova's track record and Kuroda's age, it's not particularly surprising. Plus, these projections do often skew conservative.
Aside from the statistics, though, the pitchers also looked different during their good and bad stretches. Upon his return Nova seemed to finally have sufficient control over his out pitches. His command was to the point that he was leaving fewer hittable mistakes and producing fewer unnecessary walks. Kuroda, meanwhile, seemed to be leaving his pitches up in the zone and was allowing home runs at a phenomenal rate. If Nova had truly come back from the minors a changed pitcher and Kuroda was merely suffering from arm tiredness (and hopefully not just showing his age), then those aforementioned projections could be severely underestimating just how good the two pitchers could be at the outset of the new season.
That's obviously the best case scenario. The worst case would be that Nova simply had a great run of a fairly small sample of games and Kuroda both pitched over his head early in the season and has left his best days behind him. If you were to put a gun to my head (the nerve of you) and ask how I thought these two would perform in 2014, I would say to expect something similar to Kuroda's projections, a good but unspectacular season. I'm very high on Nova, however, and anticipate something much more like his last two months of 2013 than his first three. When push came to shove I would bank on the realized development of the young pitcher and the slightly decreased effectiveness of the older pitcher. But they could give the Yankees any manner of performance in 2014 and I would not be shocked.
Amazing thing is, even after all that, Nova and Kuroda are probably the most predictable ones on this entire crazy starting staff.