Amidst all the hustle and bustle of the holiday season, FanGraphs released their 2017 ZiPS projections for the Seattle Mariners. Developed by Dan Szymborski, ZiPS is one of three highly regarded projection systems—the other two being Steamer and PECOTA. Since the Steamer projections have been available since the beginning of the offseason, we now have two projection systems to compare.
First, some notes about projection systems and my methodology. Projections are not perfect. Every system makes some assumptions about future performance and what we see are best estimates for a player’s true talent. As we receive more data about a particular player, we become more confident in those estimates. Similarly, as we receive more projection data, we can start comparing those projections to see where systems agree and disagree.
ZiPS doesn’t produce projections that are based on projected playing time while Steamer produces projections that are based on the FanGraph’s depth charts. To start comparing these two projection systems, I scaled the ZiPS projections based on the projected playing time that Steamer uses. It’s not ideal but it’s easily implemented.
Using the raw data from both projection systems, I built a rough win projection for the Mariners. Using the BaseRuns formula, I took the projected data and calculated expected runs scored and expected runs allowed for the Mariners in 2017. Then I threw those numbers into the PythagenPat formula to come up with a win projection.
ZiPS is pretty pessimistic about the Mariners’ pitching staff, driving the overall win projection towards .500. We’ve talked about it over and over again and we’ve heard it from Jerry Dipoto himself; this team needs another quality starting pitcher. Bumping Nate Karns or Ariel Miranda from the rotation would mean either one of them would be receiving the innings someone like Cody Martin or Rob Whalen is projected to receive. One additional starter won’t push this pitching staff into elite company, but it will certainly be an incremental improvement.
Neither projection system thinks the offense will reach the same level of success from last year but it’s still an above average lineup. Jean Segura’s projection is rather low but that’s understandable since he’s coming off a career year in Arizona. The outfield corners are also areas of weakness, with Ben Gamel looking particularly bad. Luckily, both Steamer and ZiPS look encouraging for his platoon mate Mitch Haniger.
Projecting the current roster for 83-87 wins in 2017 seems pretty fair. There are some solid pieces in place, but to reach the high end of that projection everything needs to go right. The average win total of the ten Wild Card teams since 2012 is 89.8. The Mariners’ project to fall just short of this mark but are certainly in contention for one of these berths.