Step 3) The Final Projection

Plugging all the numbers into the tool, I arrive at the following approx. line for Trea: 640 PA, 20 HR, 100 R, 75 RBI, 55 SB, .290 AVG. Compare that against Steamer: 629 PA, 17 HR, 95 R, 66 RBI, 49 SB, .297 AVG. The overall $ value changes from $32 to $35.6 after this adjustment!

Pitcher Projection - Robbie Ray

Step 1) The Basics - IP, K, BB

For pitchers, if we project IP, K, BB, we're already 80% of the way to a good projection. This will be the most important part! The example here will be Robbie Ray, who is really interesting to project this year, as he's gone guardrail-to-guardrail on his luck-based stats the last two years (terrible in '16, great in '17) and has the complicating factor of the new Arizona humidor.

IP

Steamer: 168 IP, 29 GS

2017: 162 IP, 28 GS

2016: 174 IP, 32 GS

Steamer sees Ray as keeping similar IP/GS to last year, but has him projected for only 29 GS. I'll bump that up to a full season (32 GS) and put him conservatively at 180 IP. That'd be a career high, but not by much, and even if there's an injury somewhere in there, I'm willing to believe he's bought a bit more manager trust (and therefore longer outings) after his stellar 2017.

K% and BB%

Steamer: 29.4% and 9.8%

Career: 27.1% and 9.5%

2017: 32.8% and 10.7%

You'll note that I use K% and BB% in this case, which are generally more reliable/consistent stats than the raw K/BB numbers. These will be calculated for you in the tool, and they update as you change all the other inputs in the tool. As I input raw K/BB projections, these are the numbers I'm actually watching. In terms of K%, Ray took a big step forward in 2016 and another small step in '17, but the walk rate has actually gotten a bit worse. Steamer shoots somewhere between '16 and '17 on both, which strikes me as reasonable. I'll push both numbers a bit up from Steamer, projecting 235 K and 80 BB (translates to 30.7% K% and 10.5% BB%).

Step 2) The Hard Part - BABIP, HR/9, Team W

Now I'll take a look at historical stats and xStats to see if we need to adjust the 'luck' stats, along with including a projected win total for the Diamondbacks to scale Robbie's expected W's.

BABIP

Steamer: .295

Career: .319

2017: .267

xStats '17: .304

First off, I think it's wise not to fully buy into the .267 BABIP Ray managed to post last year, but he certainly also seems to have reached a new level with respect to contact suppression (ie he is definitely better than the .319 career BABIP). We can confirm this looking at the 2017 xStats, where the exit velocities and launch angles allowed say he should have allowed a .304 BABIP. Based on that, I'm going to be more pessimistic than Steamer, and set Ray's BABIP at .305.

HR/9

Steamer: 1.12

Career: 1.11

2017: 1.28

xStats '17: 1.18

Based on Robbie Ray's previous reputation as a good K/BB, bad ERA/WHIP guy, you might be surprised to hear he's historically been average (or better) at allowing HR's. His big problems have really stemmed from BABIP and LOB%. So, Steamer's 1.12 HR/9 seems fairly reasonable! Sort of. I'll note that since his big step forward in '16, he's allowed more HR's (1.24 and 1.28 HR/9 past two years). But more importantly, the humidor is coming to Chase field! I have seen estimates in the range of a 35% reduction in HR's at Chase this year. Allow me to make an oversimplification here, and say that this could translate to an overall 17% reduction in Ray's HR/9 (since he plays half his games at home). I'll set 1.25 HR/9 as the baseline, so reducing that by 17% gives a 1.04 HR/9! People are seriously going to underestimate the possible effects of the Chase humidor.

Team W

FanGraphs: Diamondbacks, 84 wins

Nothing exciting here. Pitcher W projections are highly arbitrary and inaccurate, but we'll at least scale that by the expected Win% of Ray's team.