WHIP (Walks-Plus-Hits-per-Inning-Pitched)
Here, the 2021 Rockies rotation is currently in fifth all-time with a WHIP of 1.38 across the first 23 games. The 2018 rotation, which recorded a WHIP of 1.29, is fairly close to this mark, and a decrease in the walk problem (that we’ll have more on in a moment) could help put the 2021 rotation over the edge.
Here, we finally have a point solidly in the 2021 rotation’s favor. They lead the franchise so far in OPS (OBP plus Slugging), only allowing an OPS of .706 to start off the year. In second is the year 2010, which only allowed an OPS of .723. I won’t dwell on this because OPS can have outside effects like ERA due to things like defense.
Now we get into the more interesting statistics.
SO/9 (Strikeouts per nine innings pitched)
The 2021 rotation currently ranks second in this category with 7.46 SO/9, behind 2018 who has more than a whole extra SO/9 on 2021 with 8.53 SO/9.
This is not quite a point in 2021’s favor, but it shows that they are in the running to be the best.
BB/9 (Walks per nine innings)
Unfortunately, BB/9 is currently the main thing holding the GOAT title back from the 2021 rotation.
Currently, BB/9 is currently at the highest rate in franchise history, at 4.50 BB/9. This is just barely above the 4.48 BB/9 mark set by the 1999 rotation. The top three in this category? Only three of the best Colorado Rockies seasons in history. 2017, 2018, and 2007 hold these spots with 2.26 BB/9, 2.97 BB/9, and 2.98 BB/9, respectively.
So how does the ranking shake out?
Well, I set out in this article looking for the best, but in order to do that, I need to take my data and be as objective as possible with it. I took each category that I ranked and weighed them separately. I weighed SO/9 and BB/9 higher, and I weighed W% and OPS lower as both could have non-pitcher-related effects.