What if the Colorado Rockies had not traded Nolan Arenado to the St. Louis Cardinals?

With run differential, how much of an impact would Nolan Arenado have had on the Colorado Rockies?

Now for the Run Differential question, we aren’t comparing Nolan to individual players, but his spot in the lineup.

What do I mean by that?

Well, Nolan batted 3rd for the Rockies, and we can assume he would have continued to do so if he remained on the team. The reason this is important is that, unless you hit a home run, other batters are mostly responsible for your runs.

Hence, why we are going to look at how many runs the 3rd lineup spot had for the Rockies this year.

Assuming Nolan could get on base at around the same amount of times as Charlie Blackmon, how many more times would he come around?

Using this raw math, Nolan would have touched home base at least eight more times than the 3rd batter did for the Rockies in 2021. Only 8? That can’t be right, can it?

Well, you’re kinda right, an important part of modern baseball is park-adjusted stats.

When half your games are at Coors Field, as much as the “Coors” effect is overblown, there is still a slight offensive boost gained by playing in the ballpark.

This is actually the opposite in St Louis, as Busch Stadium is actually a pitcher-friendly ballpark.

So, when considering what Arenado’s numbers would have looked like, we first adjust his numbers to neutralize them and then adjust them again to playing in a Coors environment. The full formula to adjust numbers from Busch Stadium to Coors Field goes as such,

• (Stat / 2) + (Stat / (.92 * 2)) = neutralized stat

and then

• (Stat / 2) + (neutralized stat * 1.12 / 2) = Coors Stat

With that in mind, we must finally consider the roughly 49 PA (Plate Appearances) that Nolan would have been resting for. To calculate this we just scale how the 3rd lineup spot for the Rockies did this season from 702 PA to 49 PA.

With all that considered, we would see the Rockies lineup score about 110 runs, 12 more than they could produce in 2021.

Simply touching the bag, though, is not the only way a player produces runs. They can also help other players score. RBIs are king in baseball, and how other players can score is often much more important than how many you can score yourself.

Using similar calculations to before, we can see that the 3rd lineup spot (almost entirely Nolan) would have created about 124 RBIs, which is 26 more than the Colorado Rockies had in the 2021 campaign. We can logically assume then that simply keeping Nolan Arenado on the roster would have created around 38 extra runs for the Rockies offense.

But offense isn’t all that matters, is it?