See the first entry on pitching for an explanation of the method being used here.
#1. Dodgers: Hyun-Jin Ryu (2.6 WAR, #36 overall)
Four of the top 36 projected pitchers in baseball. Four of the top six in the National League West. Yeah,. I think it's safe to say that Los Angeles can call their rotation a strength as we go into 2015, though of course, who knows what might happen with health and effectiveness once the actual games begin. We saw that a bit with Ryu, who made only 26 starts for LA, and his ERA went up on his rookie season, from 3.00 to 3.38. However, both his K- and BB-rates went in the right direction, and he was somewhat the victim of bad luck, with a .319 BABIP, which would seem to augur well for his 2015 campaign.
#2. Rockies: Jhoulys Chacin (1.3, #108)
Again, a long drop-off from the Dodgers' starter to the comparable members of the rotation for the other members of the NL West, with the next three basically inseparable. Like Ryu, Chacin also had his health issues last year, shoulder problems holding him to 11 appearances, and mediocre ones at that, going 1-7 with a 5.40 ERA. Given he had posted a 127 ERA+ over the previous four seasons, there is ground to think it was an aberration, and Colorado will certainly be hoping so. Chacin opted out of Venezuelan ball and spent all winter in Scottsdale, rehabbing his arm at Salt River. A free-agent at the end of 2015, he'll want to make a good impression on potential employers.
#3. Padres: Ian Kennedy (1.3, #110)
Former Diamondback Kennedy is also in his last season before free-agency, with San Diego paying him $9.185 million for this year. Once you park-adjust IPK's numbers, he has been kinda meh for them, with an ERA+ of 89 over 43 starts since his trade-deadline deal from Arizona in 2013. However, he was slightly more BABIP'd to death than Ryu (.320) in 2014, and at 91.8 mph, his average fastball was two mph faster than it was in 2012, which helped lead to a career-high strikeout rate of 24.5%. If he can reproduce that in 2015, I'd be inclined to take the over on the projection here, though I severely doubt he'll approach anything like the remarkable 21 wins he had for us in 2011.
#4. Giants: Matt Cain (1.2, #113)
Remember when Cain was going to be the ace of the Giants rotation, signing a $127 million deal on the even of the 2012 season? Well, San Francisco got one good year out of it, at least. But in 2013-14, Cain has a 10-17 record to go with an 85 ERA+, the $40 million received being repaid with exactly one WAR of production. He missed half the season with a bone spur in his elbow, so will first have to show he's healthy, then that he can still pitch at the level where he finished 8th and 6th in Cy Young voting. If he doesn't, with three years left at $21 million per, this is going to be a nasty impediment to the Giants for some time to come. Are we allowed to hope for healthy ineffectiveness?
#5. Diamondbacks: Allen Webster (0.5, #141)
Something something upside. That said, this is where things start to get seriously murky, because there's no guarantee Webster will be in the 2015 rotation, not least because I think he still has a minor-league option left [trying to find out such things for sure is difficult, but he has only two major-league seasons to his name at this point]. The front-office has been making all the usual noises about decision being based on performance, but you're not going to try and squeeze an established pitcher through waivers, when you can open up a slot by sending Webster to the minors. I have a feeling that's what we'll see happen in late March.
There's a real smorgasbord of arms here. We have under-performing former aces, several pitchers coming back from health issues and a prospect with potential who might not even have a job on Opening Day. All of which means the projections should be taken with even more caution than usual. At their best, almost all of the above (save Webster, obviously, due to his limited experience) have already shown that they can pitch with the best of them. However, none of them did in 2014, for a variety of reasons. One or more will likely breakout, but as to who that might be, your guess is as good as mine!