While there is no shortage of quality baseball projections, in large measure they are single numbers representing some measure of central likelihood such as a weighted average or median expectation. This is only half the story, as the compliment to average is the variance and shape of the distribution. Accordingly, this is an attempt to build out projections that incorporate both dimensions. For more background, see here.
These distributions are based on projecting playing time (PA/IP) and productivity on a seven point scale on each dimension to create a 7x7 matrix of 49 outcomes. The seven points roughly correspond to the 5th/20th/35th/50th/65th/80th/95th percentile outcomes on each dimension. I’ve used the public projection systems to guide the inputs, but also incorporating my own expectations (biases).
Quality is not a concern with Ryu, at his worst he’s been roughly MLB average and the last few years almost ethereal with a 55 ERA- and similarly stunning 72 FIP-. Even that has to be regressed substantially, but he still gets projected at ace level and it gives rise to a long upside tail given the dominant track record and pitchability.
The bigger risk is staying healthy and how many innings he’ll be on the mound for. He only averaged 130 innings from 2017-19, and even coming off no issues in 2020 that has to be the ballpark for a base case scenario. The combination of age and history suggests significant chance of missing substantial time. That results in quite a few scenarios where overall production is limited, hence the shape of the distribution.
A couple of the projection systems are very bullish on Ray, forecasting above average run prevention with Steamer at 4.29 ERA and ZiPS at 4.15 ERA. This strikes me as excessively optimistic as a base case given only the collapse of 2020, but also the multiyear persistent trend of allowing more batted ball damage. I’d see it as more of an above average outcome. Further on the higher end would be a return to the 2015-17 form when he was one of the better young pitchers in baseball.
On the playing time front, Ray has never been an innings eater, but has been pretty durable and should be a pretty good bet for 20-30 starts and between 100 and 150 innings. In some respects, he’s a bit more of an extreme version of J.A. Happ 1.0, oscillating between dominant and frustrating outings with a pretty fine line between them.
Normally, a distribution shouldn’t have substantial mass past -1 WAR, since WAR is a counting stat and players who are really bad will lose opportunity and limit the total negative. In this case, the team’s lack of established pitching is likely to mean that Matz gets a good run even if he struggles really badly as in 2020. That serves to create an extended left tail compared to if the team had more depth.
Quality wise, Matz’s career has been all over the place, with fringe-average years in 2018-19 before the collapse last year. However, it’s been since 2016 that he was above average in preventing runs. There’s some chance that he re-finds that form, but more realistic would be the backend type he was a couple years ago. Regardless, he’s never thrown more than 160 innings, so isn’t going to pile up innings.
Stripling has been used as a swingman, but he’ll start the year in the rotation and I suspect spend most of the year there unless he really struggles so he gets projected on that basis. Nonetheless, it’s a lower projected innings count given that role and likelihood of having shorter “twice through the order” starts even if he makes 25-30 starts.
He had carved out quite a niche in this role with strong results for the Dodgers before, and getting back to 10-20% better than league run prevention implies a fair bit of upside. But beyond 2020 going pear shaped, it remains to be seen how those results would translate to the high octane AL Easy from the more sedate run scoring environment of the NL West.
Like Matz, Roark is going to get innings at least to start the season for lack of other options, and given the contract. A repeat of 2020’s performance if he’s done as an effective starter would result in sub-replacement level drag. The upside would be reprising his long track record as a mid-rotation starter, but numerous factors point towards that as less likely the former. The bulk of the scenarios end up in the middle, where he’d be more of a backend type, filling some serviceable if uninspiring inspiring innings to give the bats a chance (~5.00 ERA).
The big wild card. He’s going to miss the beginning of the year, which actually doesn’t have a significant impact on the projection since he was likely to have his innings capped anyway so that can give him a longer runway later into the season. Even looking past that though, he’s still a pitcher who missed a big chunk of 2020, 2018 (two different injuries), and barely pitched for two years in college.
Likewise, the run prevention is a matter of significant uncertainty. His four starts in 2020 were disappointing, and he still has to prove he can translate his arsenal as a MLB starter. It’s worth ratcheting back base case expectations some compared to where they would have been in 2020, but the huge raw stuff provides every reason to believe he will in time. That gives rise to a significant upside tail, limited compared to others only by the limited innings outlook.
Note: “ERA” is shorthand for estimated run prevention ability (think a mix of bottom line runs allowed results and FIP-type peripherals of the factors pitchers most control), and is based on league average being similar to 2020 (~4.45). Pure ERA would be would more inherently volatile and result in wider distributions than reflected above.