Shocking Stat Proves Just How Good Ryne Nelson Was in 2025

Nelson's four-seam was worth a +23 Run Value. That is tied for the highest-value fastball in baseball, right next to young phenom Paul Skenes and his own four-seam. In fact, the only pitch more valuable than Nelson's (and Skenes') fastballs was Tarik Skubal's changeup — worth +25 Run Value.

So what is Run Value? Run Value is defined as "the run impact of an event based on the runners on base, outs, ball and strike count," per Statcast Glossary.

In the simplest possible terms, Run Value takes factors like velocity, spin, location and other aspects of a pitch to determine whether or not that pitch increased or decreased a team's chances to prevent a run.

Now, granted, that value does rise a bit due to the fact that Nelson relies so heavily on the fastball. But his four-seam is a legitimate weapon, and quantifiably one of the best in the sport.

The pitch averages around 96 MPH, but has climbed as high as 99 on occasion. Opponents hit it at a .207 clip in the 2025 season, though he only collected swing-and-miss on the pitch at a 19.1% rate.

As a whole, Nelson's 2025 season was extremely successful. Though the right-hander was initially relegated to bullpen duties, he was awarded a chance to re-enter Arizona's rotation once Corbin Burnes went down with an elbow injury.

Nelson pitched to a 3.16 ERA as a starter, making 23 starts over 128 innings. He was the D-backs' most consisent starting pitcher, and may be in line to start come 2026 Opening Day, depending on how Arizona deals with its rotation this offseason.

"I always believed in myself, and I always knew what I was capable of, and the one thing I'm most proud of is that with the moving around, I never lost that belief in myself," Nelson said.

"Sometimes you can take a role change as a shot at what other people think of you, but I never really took it that way, and I always believed that I am good enough to be a starter in this league."

Related Content: How Ryne Nelson Became Diamondbacks' Best 2025 Starter