What is the best case scenario for the Yankees starting rotation?

There has been plenty of consternation this offseason about the shaky state of the Yankees’ pitching staff. The team enjoys the benefit of employing ace Masahiro Tanaka, but beyond him, the rotation is littered with question marks (and even Tanaka himself has a bit of an injury history). CC Sabathia was strong last season, but he’s old, and Michael Pineda is forever confounding. Younger pitchers like Luis Severino and Chad Green are unproven.

Still, on the whole, the baseline from which the Yankees pitchers are starting isn’t a complete disaster. In 2016, the Yankees starting staff ranked 16th by fWAR and 12th by RA-9 WAR, middling but far from awful. FanGraphs projections peg them as the 13th-best rotation headed into 2017. The outlook is far from picturesque, but it could be worse.

However, what kind of top-side potential does this staff have? Last season, with the help of Baseball Prospectus’ PECOTA projections, I took a look at what a best case scenario for the rotation would entail. I used what are called percentile forecasts, which PECOTA generates for every player. Essentially, if PECOTA gives an 80th percentile forecast of a 4.00 ERA for a pitcher, then there’s an 80% chance that the pitcher posts an ERA of 4.00 or worse.

If everything breaks right for the Yankees’ staff, their pitchers would all hit, say, their 70th percentile projections. So, let’s take a look at the 70th percentile forecasts for all the Yankees pitchers to get a sense of the unit’s potential:

At first glance, PECOTA does not seem to think that the staff has as much upside as it did entering 2016. The group’s combined mean projection and 70th percentile projection are each about a win lower than last year’s figures, despite higher innings pitched projections. The staff’s 70th percentile ERA is also nearly three-quarters of a run higher than last year’s 70th percentile ERA. Part of that can be accounted for by a higher run environment, but it’s still a noticeable increase.

Why does PECOTA see the rotation’s ceiling as lower? First off is the notably pessimistic forecast for Tanaka. Tanaka has rated well by BP’s pitching metric DRA for the entirety of his career and is coming off an excellent season in which he set career-highs in innings pitched and WAR. That PECOTA sees a 3-win season as a 70th percentile outcome for Tanaka is puzzling.

Less strange is PECOTA’s more pessimistic regarding Severino. He projected well entering 2016 after a very promising rookie season. Now that he enters 2017 coming off a trying sophomore campaign, it would be foolish to give up on Severino, given his youth, but PECOTA is understandably less hopeful that he will turn into an above-average starting pitcher.

Sabathia’s ceiling per PECOTA has also fallen, which, even after an impressive rebound season for Sabathia, still makes sense. A 5.23 median ERA projection looks a little too pessimistic, but at age 36, Sabathia is an obvious candidate for regression.

Elsewhere, replacing Nathan Eovaldi with players like Bryan Mitchell and Luis Cessa has taken a hit to the rotation’s upside. Eovaldi’s 70th percentile forecast from last year called for 167 innings of above average pitching, a forecast that none of the Yankees’ young arms have reached this year.

Overall, PECOTA paints a less rosy picture about the best case scenario for the Yankees rotation. A 13.7 WARP projection would still only rank the Yankees fourth among AL starting staffs. Plus, as PECOTA pegs the Yankees for 80 wins in 2017, even if the rotation hit on something like a best case scenario and produced five more wins than expected, it might not be enough to make the playoffs.

There are areas where the Yankees look likely to prove PECOTA overly pessimistic (mainly with regards to Tanaka), but that might not be enough to push the staff over the top. It will be up to the lineup to make up the difference and over compensate.