The Diamondbacks acquired Nolan Arenado. He has won 5 Silver Slugger awards, 10 Gold Glove awards, and 6 Platinum Glove awards. And yet his batting declined to near average in the last couple seasons. What happened? Will he impact the Diamondbacks?

The context of his batting decline was that even in decline his batting has some awesome characteristics. Three characteristics follow:

11.2 K% was at the 96th percentile.17.9 whiff % was at the 85th percentile.28.8 squared up % was at the 76th percentile.

His batting decline can be understood in at least three ways. Let’s look at each explanation.

Injury. In June he injured his finger. He played through the injury by adjusting his swing. On 11 July, he aggravated the injury. Later in July, his adjusted swing was likely responsible for his shoulder injury. He was on the injured list until September.

Nolan Arenado regrets that he played through the injury instead of immediately addressing it.

“If I could do it all over again, I probably would have just taken time [on the injured list] when I hurt my finger — that was probably the biggest mistake I made.”— Nolan Arenado

Less Pulled Baseballs. Looking at his balls in play, the percentage that were pulled fell from 46.9% in 2023, to 44.2% in 2024, to 42.1% in 2025. That is significant because in 2025 his monthly (ignoring July because it was the injury month) OBP/SLG/wOBA stats shown in Baseball Savant were consistently awesome for pulled balls in play, but below average for straightaway and opposite field balls in play. In September, he showed potential for average results to the opposite field.

For an obvious reason, it is easier to pull the ball when contact is made farther in front of the plate. Perhaps he pulled a lower percentage of balls because he hit the ball closer to the plate. His average contact point changed from 4.8”/4.9” in 2023/2024 to 3.0” in 2025 when league average was 2.9” per Baseball Savant.

“I think some of the adjustments I’m trying to make, and the adjustments that I’ve talked with the hitting coaches already about are going to pay dividends down the line….quiet my head, see the ball better, and hopefully create space for me to work out front again. That’s when I’m at my best is when I’m pulling the ball out front.” — Nolan Arenado

Busch Field was unlucky. To some extent, in 2025 Nolan Arenado was unlucky with Runners in Scoring Position (RISP). While 30.5% of his PAs were with RISP, only 26.5% of his hits were with RISP, and only 8.3% of his homers were with RISP per Baseball Savant. If his batting had been consistent, even with RISP, his SLG and Runs Batted In (RBIs) would have been higher.

Moving from Busch Field to Chase Field will be a positive change. Park factors show he will hit more doubles (park factor increases from 105 to 115) and triples (park factor increases from 81 to 204). More doubles and triples will improve his SLG and RBIs.

In the context that the last time he won a Gold Glove award and a Platinum Glove Award was 2022 (when he won both), and that as he ages his defense will decline, I am confident that he is an outstanding defender at third base.

In 2025, his 2.4% errors per attempt was a career best. His 98.2 fielding percentage and his 2.84 Range Factor per 9 innings are above league averages.

His strength will be fielding ground balls hit to third base. In 2025, his 85.3% positive results with ground balls compared favorably to the Diamondbacks’ 77.7%. (Also, his positive defensive results increased slightly with RISP.)

My view is that his strength will most improve the results of Diamondbacks pitchers who had the highest percent of ground balls towards third base. The following table shows the pitchers who will benefit the most. 2025 Data from Baseball Savant.

Impact on Diamondbacks Wins.

Batting. My subjective estimate is that his impact will add 10 runs scored. That is roughly equivalent to one additional win. That is based on the following assumptions:

No re-injuries to his finger or shoulder.He pulls more balls by contacting the ball farther in front of the plate.He hits at least as well with RISP as without RISP.He hits more doubles and triples at Chase Field than Busch Field due to different park factors.

Defense. My subjective estimate is that the impacted pitchers will allow 10 less runs due to Nolan Arenado’s strong defense. That is roughly equivalent to one additional win.

Nolan Arenado will add two wins to the Diamondbacks.