SEATTLE — In 2022, Seattle Mariners phenom Julio Rodriguez set the league on fire in his rookie season.
Rodriguez hit 28 home runs (second on the Mariners), stole 25 bases (first on the team), totaled a .284 batting average (second on the team) and changed the trajectory of the franchise in just one season. He wowed during the 2022 Home Run Derby, narrowly losing to a player many consider one of the best players in the game in the final round.
Everything was coming up Julio in 2022 and it seemed he was a good bet as any player in baseball to ascend into one of the league's defining players.
For his efforts in a standout rookie season that earned him American League Most Valuable Player votes (he finished seventh), the Mariners inked the 21-year-old to a 14-year contract extension of at least $200 million guaranteed. If he reaches certain incentives, Rodriguez could earn well over $470 million in his contract.
Then the year turned to 2023 and... something changed.
Rodriguez was demoted from his leadoff position and dropped to sixth in the Mariners' batting order on May 10. Shortstop J.P. Crawford was inserted into the leadoff slot in Rodriguez' place. It's unclear if this change will be permanent, but Rodriguez' fall from the unquestioned best hitter on the team to batting behind Eugenio Suarez is a stunning change in a short amount of time.
So what on earth has happened to Julio this season? And should we be concerned? Let's break it down.
Julio's hitting profile
Rodriguez' numbers have dropped significantly in batting average, on-base percentage and slugging percentage in 2023. He's hit six double plays in 2023. He grounded into seven double plays in the entire 2022 season.
But traditional counting stats don't really tell the whole story; they merely describe what we can all see. Rodriguez has struggled at the plate.
Here's where Baseball Savant, an advanced MLB statistical database that tracks about everything you could possibly imagine, comes into play for more nuanced analysis.
The site calculates Expected Batting Average (xBA) and Expected Slugging Percentage (xSLG) based on the likelihood of batted balls to become a hit, rather than just the actual result. For example: Rodriguez had a .284 batting average in 2022, but he was expected to have a .254 batting average based on the quality of his contact, according to Baseball Savant. Put simply, he overperformed his expected stats. That can happen for a variety of factors including blind luck or in Rodriguez' case, having prodigious speed helps turn certain opportunities that would be guaranteed outs into singles because he can beat out the fielder's throw.
Here's the weird kicker: Rodriguez' expected batting average this season is actually higher in 2023 than in 2022. His expected slugging percentage is nearly as high as his impressive rookie season, complicating the picture further.
Here we have a player that should have a higher batting average than last season and is hitting for comparable power. Yet, he's a below-average hitter compared to his MVP-caliber year in 2022 when he was 46% better than the average MLB hitter. This season he's been 9% worse than an average hitter, a mark befitting sparingly used bench hitters, not the franchise centerpiece that Rodriguez is. In fact, five players on Rodriguez' own team have been more productive hitters at this point in the season.
Julio's plate discipline
So could Rodriguez' struggles be tied to a change in plate discipline?
Not necessarily. While his strikeout percentage (which was already high) has jumped from 25% to 29% in one season, his other peripherals are largely the same. He's swinging at pitches in the strike zone and chasing pitches out of the strike zone at the same rate as his rookie season, according to Baseball Savant. He's just striking out plenty more.
Rodriguez is swinging at the first pitch 34% of the time, down from his 39% mark in his rookie season. That really can't be the sole explanation for his down numbers, especially since his walk rate is essentially the same this season.
Maybe there's something more going on.
Pitchers changing approach against Rodriguez
In 2022, the book on Rodriguez was to not throw fastballs against him because he crushed that particular pitch. According to Baseball Savant, Rodriguez mashed fastballs with a .317 batting average, slugged over .500 and he rarely whiffed on the pitch. Fastballs were bad, bad news against Rodriguez.
Rodriguez was about league average against pitches classified as "breaking" and below-average against "offspeed" pitches, according to Baseball Savant. This paints a clear picture of attack for opposing pitchers: Dial down the fastballs and instead lean on secondary pitches to put Rodriguez out. It's worth noting, however, this is the standard approach in the modern game for any hitter and not really exclusive to Rodriguez. The strategy is just much more exaggerated because of how good Rodriguez was against fastballs last season.
As a result, pitchers tossed Rodriguez fastballs on 51% of their pitches in 2022 and tried to beat him with other offerings. It didn't really work given Rodriguez' success across the board but that was the main idea, after all.
Yet Rodriguez has seen more fastballs in 2023 than last season despite a year's worth of evidence proving fastballs are the worst pitch you could possibly throw to Rodriguez. He's still struggling. Pitchers have leaned on the fastball 55% of the time this year, a dramatic shift in approach that runs counter to the previous strategy.
The biggest and most identifiable difference in the first two seasons of Rodriguez' career has been going from an elite fastball hitter to an abysmal fastball hitter in just one calendar year. Rodriguez is hitting fewer fastballs (.200 batting average), striking out much more often, hitting fastballs at a lower exit velocity and not generating the same power as he did in 2022 when he set the standard against the fastballs.
Major league pitchers, sensing a difference, have responded in kind by throwing him more and more fastballs (which seems kind of mean if you ask me).
Rodriguez' best pitch to hit this season has been "breaking" pitches but his effectiveness against these pitches remains barely above average, according to Baseball Savant.
Instead of pulling the ball, Rodriguez is hitting weaker contact to right field – much easier outs for defense than when they are watching the ball smacked over the fence.
The issue is compounded further because Rodriguez' inability to hit the fastball at the same clip allows pitchers to hammer him in the strike zone, get ahead in the count and rely on devastating secondary pitches to strike him out.
Everything starts and ends with Rodriguez' success against the fastball. It's a type of pitch he decimated in 2022 and allowed him to get the advantage against pitchers, not the other way around.
Now he's being bullied by fastballs, turning him into a reactionary hitter and sapping him of his best skills as a hitter.
Is there anything positive here?
It's a microscopic sample size, but Rodriguez has hit for a .292 average, gotten on base 37% of the time and hit for a home run in six games since he was moved from his leadoff spot in the Mariners order. He was hitting just .204 and getting on base just 27% of the time in his first 34 games as the team's leadoff hitter.
Rodriguez is still incredibly young and his prodigious ability has not vanished overnight. He's still hitting the ball hard enough to be a successful hitter, paired with top-of-the-line speed that helps him as a defender and baserunner.
The Mariners phenom just needs to find a way to hit the pitch that he absolutely crushed in his rookie season.