Michael Frain: An Analysis of the Paul Goldschmidt Trade and Why the Diamondbacks Won

This article is by guest author Michael Frain

On December 5th, 2018, the St. Louis Cardinals acquired first baseman Paul Goldschmidt from the Arizona Diamondbacks in exchange for a package of prospects containing Carson Kelly (C), Luke Weaver (RHP) and Andy Young (INF) as well as a 2019 Competitive Balance Round B Draft Pick. Keep in mind that all of this was in exchange for a player that only had one year of team control left. Goldschmidt did sign a 5-year extension in the months following his departure from Arizona, but at the time he only had 1 year left on his contract. Along with the fact that the Cardinals didn’t get a ton of value back in this transaction, there are three other factors that led to the D-Backs coming out on top in this trade.

To begin, we have the prospects Arizona received. Starting with Carson Kelly, who had an offensive revival with the Diamondbacks last year posting a 108 wRC+ (Weighted Runs Created Plus) as well as a .337 xwOBA (Expected Weighted On Base Average). His previous career-high wRC+ was a measly 26 in 2017, which is terrible considering 100 is league average. So what did he do to become more successful at the plate? For starters, he doubled his career walk rate of 6.5 in 2019. He also hit the ball a lot harder, which is evident by his Hard Hit % rising from 25.8 in 2018 to 40.4 in 2019. It’s worth noting that he had a higher fWAR in fewer games than Yadier Molina last year, the Cardinals current catcher, who is regressing very quickly. This along with the fact that Kelly is controllable through 2025 will make the Cardinals wish they never let go of the young backstop. The next player the D-Backs acquired was Luke Weaver, a starter, who posted a sub-3 ERA for the first time in his career in 2019. Despite his xFIP (Expected Fielding Independent Pitching) floating .80 points higher than his FIP, suggesting he got very lucky last year, he looks to be a solid arm for Arizona in their rotation, especially considering he is controllable through 2024. The final prospect the Diamondbacks acquired was infielder Andy Young, who hasn’t reached the majors yet. In AAA last year, he posted a very respectable 131 wRC+, with a wOBA over .400 and a SLG over .600.

Another factor that determined the champion of this trade was Goldschmidt’s performance in 2019. Last year we did not see the vintage Goldy we have become used to for the past decade. His wRC+ dropped from 146 in 2018 to 116 in 2019, as well as a .043 point decline in his wOBA between the last 2 years. Defensively, he regressed big time, failing to save any runs after posting a DRS of 11 in 2018. His offensive counting stats appeared to be elite, but the advanced metrics show the Cardinals did not get the player they were expecting.

Cred. Dustin Bradford/Getty Images

The Diamondbacks dealt one final blow to secure the transaction’s victory and it had nothing to do with this deal at all. This is how easily they were able to find Goldschmidt’s replacement; through a waiver claim. Yes, I know it sounds shocking, but the D-Backs waiver claim from 2017, Christian Walker, outperformed Paul Goldschmidt last year. Offensively, they each posted a 119 DRC+ (Deserved Runs Created Plus), which is essentially wRC+ but it accounts for the quality of teams a certain player faced. The area in which Walker is far superior is on defense. Walker posted a DRS of 11 last year, compared to Goldy’s 0 in 2019.

In the Cardinal’s defense, Kelly and Weaver were coming off terrible and below-average seasons respectively, so it’s fair to say that no one saw this coming.

To conclude, the Diamondbacks received a starter with great upside, an above-average catcher with future potential and an infielder who is developing very quickly in the minor leagues. They acquired all of this for a player that was essentially replaced by a waiver claim. Not bad if you ask me. As for the Cardinals, they are really going to wish they never lost these players. Kelly would clearly be their catcher of the future considering Molina, the 37-year-old veteran, is now a below-average hitter and barely above-average defender, with a DRS of 2 in 2019. Having Weaver would really strengthen the middle, perhaps back end of their rotation, especially with Miles Mikolas’ recent injury and Adam Wainwright’s age concerns. With that being said, there’s still a lot more that needs to be seen when it comes to this trade, so it’ll be interesting to see how our views may change as the careers of Weaver, Kelly, and Young unfold.