See the first entry on pitching for an explanation of the method being used here.
#1. Dodgers: Zack Greinke (3.3 WAR, #16 overall)
Los Angeles probably don't have quite the best 1-2 punch in baseball - that probably goes to the Nationals, with MAx Scherzer and Stephen Strasburg - but Clayton Kershaw and Greinke aren't chopped liver. The latter would be the ace of any other rotation in the National League West, save perhaps the Giants. One thing worth beating in mind is, that while Greinke is under contract to the Dodgers through 2018, he has an opt-out clause at the end of this season, if he thinks he can get more than the remaining $77 million. Something Max Scherzer like (seven years, $210 million) could be on the cards, if he stays healthy and pitches well in 2015.
#2. Padres: Tyson Ross (2.3, #49)
Ross might be the best pitcher in the division, about whom you've only heard vaguely. Despite a losing record last year - indeed, his career record is 22-40 - he had a 2.81 ERA, and even allowing for Petco, that still works out as a solid 119 ERA+. He gets a lot of ground-balls, and also misses a lot of bats, an extremely effective combination, with his slider particularly effective with regard to the latter. According to analysis, only three qualifying starting pitches have had a higher percentage of swings and misses than Tyson over the past two seasons: Kershaw, Francisco Liriano and Cole Hamels. That's some elite company, and this projection may be low.
#3. Rockies: Jordan Lyles (2.3, #50)
It's interesting to note Lyles and Ross are projected for the same WAR over 200 innings in 2015, even though Lyles's ERA was a full run and a half higher last year. That's partly the difference between Petco and Coors, folks, and partly Lyles still being very much a prospect, who only turned 24 in October. He came over from Houston in the Dexter Fowler trade, and given his ERA was 5.33 over 65 starts with the Astros, took to pitching in Denver well in his first season, shaving more than a run off that figure. He settled his first year of arbitration last month, and if he can improve even a little more on his 2014 campaign, will be a solid and cheap member of the Rockies rotation.
#4. Diamondbacks: Rubby de la Rosa (1.5, #94)
The key word here is "upside", but that probably depends on de la Rosa being able to lean and harness consistently a third pitch for his arsenal. Last year, he threw his fastball-changeup combo 86% of the time, which is a repertoire better suited to the bullpen than facing the same hitters three or four times in a game. de la Rosa has a breaking ball, but it's neither reliable nor effective enough to be a good option at this point. There's no denying his stuff - Rubby's fastball last year averaged 93.5 mph, and over the past decade, only Edwin Jackson has thrown harder among our starters. But that third pitch will be key in determining his success, or lack thereof.
#5. Giants: Tim Hudson (1.5, #98)
Yeah, that's a bit of a plummet for San Francisco. Indeed, the fall-off from their ace is so steep according to the Fangraphs projections, you might describe their 2015 rotation as Bumgarner + four bums. Admittedly, they are mostly extremely well-paid bums, with Hudson, Matt Cain and Jake Peavy due a cool $42 million - and that's not counting the $18 million due to Tim Lincecum, whom the projections do not expect to be in the rotation (though Bruce Bochy feels differently). After the World Series win, Hudson is "pretty sure" this will be his last season, and since he'll turn 40 in July, that makes sense.
Not a great deal here we didn't know either. Virtually every potential pitcher in the Diamondbacks starting rotation has one or more question-mark over him for 2015. In some cases, that's an upside thing, which is good; however, that upside typically comes with an "if", as in this case, "if de la Rosa can develop a third pitch." It's one of the reasons why I think 2015 will be a rebuild: the team will be looking to answer these questions, and the odds are near-certain that there will be some wrong turns and negative conclusions along the way. By season end, de la Rosa may be a valuable member of the rotation, or he may be moved to the bullpen. We'll have to wait and see.