With the release of PECOTA, there are four major projection systems that have released their data for the upcoming season. Let's take a look at how each system compares on what will likely be the primary pitchers for the Royals. Because the back end of the bullpen isn't exactly settled, I included some pitchers of whom we may not see much. Or of whom we may see quite a bit. Who knows. Position players are here. Also, here's an article going a little more in depth discussing the differences between the projection systems. A few projections are missing - ZiPS for Joakim Soria and Dillon Gee and Marcel for Brian Flynn. Notice the x axes for each graph.
I grabbed Steamer and ZiPS from FanGraphs, Marcel from Baseball Reference, and PECOTA from Baseball Prospectus. One thing to note about these projections - Steamer, ZiPS, and PECOTA are actively managed by people whose goal is to improve the projection. The Marcel projections, developed by Tom Tango, are meant to serve as a baseline which any projection system should aim to beat. Since its inception, Marcel has not been updated (as far as I know). Marcel's beauty is in its simplicity.
As noted in the title above, there's not a lot of illuminating information here. The systems appear to be fairly mixed here as opposed to the positions players, universally disliked by PECOTA. For the pitchers with a small sample size, the projections are a little more spread out. Chris Young's Marcel projection, taking into account just past performance, has a much lower ERA than the other three systems. Young is a known confounder.
Aside from those, perhaps the most noticeable thing is the spread in Kelvin Herrera's numbers. ZiPS has an ERA almost a full run lower than PECOTA. Herrera's ERA has ranged from 1.41 to 3.86 in the past few years, so it kind of makes sense. Herrera's peripherals are more like the other projections than ZiPS. He is, in fact, a reliever, so there's probably still some sample size concerns messing with the projections.
Not all the systems have K%, so you get K/9. I hope you're happy that we can't have nice things.
There is a similar phenomenon - smaller sample size = more variability. The biggest things I noticed were Wade Davis and Kelvin Herrera's projections. I'll take the bigger numbers for Wade and the smaller numbers for Herrera. Moving on then?....
PECOTA is normally at the bottom for each player, but there really isn't much of note here. Have fun there.
There's the PECOTA lukewarm dislike. The first three pitchers by average WAR, Yordano Ventura, Edinson Volquez, and Ian Kennedy, show PECOTA as their lowest projected WAR. Ventura and Volquez are disliked in particular. Given Ventura's performance to this point, I'm a little confused why PECOTA would dislike him, but his comps must be bad players (PECOTA uses comparison players in projections).
Danny Duffy, Kris Medlen, Ian Kennedy, Luke Hochevar, Chris Young, and Kelvin Herrera each have one projection system liking them more than the other two. PECOTA is the leader for only Hochevar; it's Steamer or ZiPS for the other players.
Lastly, only Steamer's Yordano Ventura projection is at least 3 WAR. You can find the data here.