Exactly how non-“playoff” was the Mariners rotation?

It’s no secret that the Mariners have performed a bit under expectations this season. It doesn’t take much digging to uncover that the injury plagued pitching staff is largely to blame for the less-than-impressive results. But exactly how much has this pitching staff under performed the expectations of a playoff team? What does a playoff rotation look like? And how can we expect--or at least hope--the team will go about making sure the same thing doesn’t happen next season?

To start, let’s take a look at the performance of the top five starting pitchers on each of 2016’s playoff teams:

Each rotation above is sorted by fWAR, with the most valuable pitcher on a team being referred to as the #1, the second most valuable being listed as #2, etc, even if the rotation isn’t necessarily listed that way on the official depth chart. For the purpose of this research, in the event that a team didn’t have five starters with a full season’s worth of starts, more than one pitcher may have been combined to generate the total fWAR for that rotation spot.

In hopes of identifying exactly what a “playoff rotation” looks like, I came up with the following list, showing the average, highest, and lowest value in fWAR from any given rotation spot from the 10 teams that qualified for the playoffs in 2016:

In looking at that list, you’ll notice that none of the 10 playoff teams received an output from any spot in their rotation that was greater than 1.9 fWAR below average. Even the least productive of #2 - #4 pitchers were still within 1.3 fWAR of their respective averages.

Now, let’s take a look at the contributions we’ve gotten from the Mariners pitching rotation to date this season:

As you can see, the Mariners rotation collective fWAR of 6.2 has been nowhere close to the 2016 average playoff rotation fWAR of 14.9. Even accounting for the last couple of times through the rotation--and that’s assuming the Mariners total goes up and not down over that span--the Mariners won’t even reach half of that number. You could have added 2016 Max Scherzer and Yu Darvish to this rotation, and that would have only brought the total to 14.2 fWAR, which is STILL short of that mark. Not trying to beat a dead horse here. We all know the Mariners rotation has been bad. Jerry Dipoto, in theory, obtained a solid rotation’s worth of starting pitchers. The projected rotation of Felix, Paxton, Iwakuma, Smyly, and Gallardo combined for 9.5 fWAR in 2016, and while that figure doesn’t exactly have you rushing out to put down a deposit for 2017 playoff tickets, each of those guys were coming off of an injury-shortened season and were thought to be healthy and therefore more productive entering 2017. Of course, things didn’t work out that way.

The Mariners did have one true top-of-the-rotation pitcher this season--when he was able to stay healthy that is--in James Paxton. While the Paxton/Ramirez combination’s fWAR of 4.3 lags a bit behind that of the “Average Playoff Team #1”’s total of 4.9 fWAR, the 4.3 mark is perfectly acceptable for an ace, and was higher than the fWAR produced by three of the 10 playoff teams aces.

The real trouble starts when you look at the #2 spot in the Mariners rotation. Ideally, Felix Hernandez would have transformed back into dominant King Felix of the early 2010’s, and James Paxton could have settled nicely in as perhaps the best #2 starter in all of baseball. In reality, Felix looked old, and injured, and ended up being worth 0.4 fWAR over 14 starts. The Mariners “#2 pitcher” ended up being the combination of Mike Leake, whose 1.2 fWAR made up the whole total of 1.2 that he and Yovani Gallardo combined to contribute in 26 starts. The 2.5 win difference between Leake/Gallardo and the Average Playoff Team’s #2 represents that largest such difference for any rotation spot contribution for the Mariners this season. Said different, no spot in the Mariners rotation underperformed expectation of a playoff rotation more than the #2 spot. In 2016, the lowest fWAR posted by a playoff team’s #2 starting pitcher was 2.4 fWAR by the Baltimore Orioles Chris Tillman. The best? Madison Bumgarner at 4.9. The contributions received from Leake/Gallardo, again, the second best “pitcher” in the Mariners rotation this season, is almost identical to the Average #5 Starter for a 2016 playoff team, which was 1.3 fWAR.

The Mariners #3 spot just barely performed better relative to their playoff expectations, with the pile of Andrew Moore, Christian Bergman, Andrew Albers, Marco Gonzales, and Hisashi Iwakuma combining for a whopping 0.4 fWAR in 33 starts. That total was 2.4 wins less than the 2.8 fWAR posted by the average playoff team’s #3. The lowest total from a #3 starter on a playoff team was Baltimore’s Ubaldo Jimenez, who checked in with 1.7 fWAR which, once again is a far cry from the contributions the Mariners received from the same spot.

Ariel Miranda slots in here as the Mariners #4 pitcher, and represents the lone spot in the rotation that was occupied by one single pitcher. Demonstrating the value in durability among starting pitchers, Miranda managed to post a 0.3 fWAR this season despite tying for the major league lead in home runs allowed at 35 (as of now). That said, even the worst #4 starting pitcher for a playoff team in 2016, Derek Holland, was three times more valuable than Miranda. With the average playoff #4 being worth 2.2, the M’s #4 came up 1.9 fWAR short.

And last, the Mariners #5 starting pitcher was comprised of a 0.4 fWAR Felix Hernandez and a -0.4 fWAR Sam Gaviglio for a cheery sum of 0.0 fWAR. That’s not gonna cut it. Grimly, other than the #1 spot, this is the closest the M’s have been this season to matching the average production from any playoff rotation spot, coming up just 1.3 fWAR short.

Here’s a quick reference table summing up all that up:

Using the 2016 playoff teams average fWAR from each rotation spot as the reference point, the 2017 Mariners rotation went 1-5-5-5-5. At best. As of the time of this writing, the M’s rotation has amassed just 6.2 fWAR this season, and would need to increase that total by 8.7 fWAR if they wanted to receive average production--compared to the rotations of the 10 playoff teams in 2016 that is--out of their rotation.

If they simply wanted to match the lowest output received from an occupant of each spot in a playoff rotation, they’d still be 1.8 fWAR short of that mark of 8.0 fWAR. Could that difference have been made up this year had that ideal starting rotation remained anything close to healthy? Perhaps, but that obviously was not the case this year, and there’s an about 0% chance we will see three of those five starters (Gallardo, Gaviglio, Iwakuma) pitching a game for the Mariners in 2018 anyways.

Improving the rotation needs to be the top priority for the Mariners and will be addressed this offseason. As a follow up to this piece, we’ll take a look at the upcoming free agent class to identify some potential fits to close that 2-3 WAR gap from the production the Mariners received from their starting rotation in 2017 to the expected production they’ll need if they expect to find themselves in the playoffs before their current window closes.