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

I have been watching Marvel’s What If…? recently. The show has me wondering about many what if’s in my life. What if I hadn’t met my girlfriend? What if I played college football? And, most importantly, what if Nolan Arenado had played for the Colorado Rockies in 2021? How many more games would they have won? They were better than everyone expected. Could they have been a playoff team? Let’s get into it.

First, let’s get something out of the way. Everything that we are looking at today is merely speculation based on Nolan’s numbers in St. Louis. He could’ve had a completely different season with the Rockies. We cannot properly account for these unknowable. Therefore, we are just going to assume Nolan Arenado would’ve had a similar quality season to that he had for the Cards if he was still on the Rockies.

What would have Nolan Arenado’s WAR looked like if he still was with the Colorado Rockies?

Nolan Arenado produced 4.2 WAR in the 2021 season for the St. Louis Cardinals. The most simple answer to determine how much WAR would have been gained if Arenado wore a Colorado Rockies uniform.

If Nolan was on the team, then immediately, you know several call ups with net negative WAR would never have happened, think players like Rio Ruiz and Matt Adams. Brendan Rodgers would see less time, and unfortunately, I doubt we would see the emergence of Connor Joe.

When those factors are considered, the 2021 Colorado Rockies would have gained about 4.0 WAR. This would equate to the Rockies finishing with a 78-84 record to end one game behind the San Diego Padres to remain in 4th place in the NL West.

For those curious, St. Louis could have lost as much as 5.0 net WAR without Nolan on their roster, finishing with an 85-77 record and still beating out the Reds by two games for the second NL Wild Card Spot.

WAR gives a good idea of a player’s impact, but I believe we can do better, let’s look at how Nolan would have affected the Run Differential.