The HardHit% Age Curve

Many indicators are pointing to Adolis García’s power declining. If so, his fantasy value may be careening down a cliff. First, Michael Bauman expressed his concerns about García’s declining expected stats, particularly in his performance against high-speed fastballs. Second, his ISO shrunk between 2023 and 2024 from .263 to .176. Lastly, his declined slugging percentage in 2024:

If you drew a straight trend line from the start of 2022 through the end of 2023, it would be a positive slope line. That’s not true of 2024. The straight line would be a negative slope for the 2024 season. Yet, in 2024 García still hit the ball hard and hasn’t necessarily shown a decline in that skill:

Furthermore, in each of the last four seasons, García has hit a ball harder than his best from the previous year (112.4 MPH – > 113.0 MPH -> 115.1 MPH -> 116.1 MPH). Again, he still hits it hard, it just may recently be coming with less quality. As Bauman pointed out, García’s losing bat speed and can’t get to fast pitches quickly enough because of it. Does that mean García has shown signs of results decline before the skills decline? Or, is this just regression plus injury hang-over after the long World Series winning campaign of 2023? That’s hard to say and this article is not about Adolis García. It’s about the power decline as it applies to players like Adolis García versus, well, everyone else. By that, I mean hitters entering the 2025 season at an age where we should expect some age decline:

The above graph was created using the delta method as described in The Hardball Times by Mitchel Lichtman. Put your finger on the x-axis 32 mark and move it up to the data line and you’ll see how players’ HardHit% starts to decline. Who do we have in that camp heading into the 2024 season? Lots of players, too many to list. Let’s focus on the ones the fantasy community is concerned with the most, the ones who have repeatedly hit the ball hard throughout their career. To get there, I’ve taken the hitters included in the age curve above, those with at least two 150+ PA seasons from 2008 and 2024, isolated the ones who have recorded an above average HardHit% in at least two of those seasons, pulled out those who were 31 or older in 2024, and focused on those who have declined in HardHit%, SLG, and wOBA from 2023 to 2024:

The table above is sortable. Take those hitters with large PA deltas with a grain of salt. For example, you shouldn’t be too concerned with Mookie Betts’ or Freddie Freeman. You should be concerned with Adolis García, Jorge Soler, Nick Castellanos, Josh Bell, and Paul Goldschmidt. While the above table focuses on the players who have declined in all three metrics (SLG, wOBA, HardHit%), of the 48 players who declined in HardHit% (no matter the PA delta), 32 of them declined in slugging percentage (66.7%) and 33 of them declined in wOBA (68.6%). If you’re a hitter known for power-moving into your early 30’s, the odds are against you regarding continuing that power.

We should be cautious, however, not to over-weight this common decline. All projection systems consider the age curve and many of the hitters listed above, still have something to offer fantasy baseball teams. If we break the age curve group in the graph above into two groups, those who have hit the ball at a rate greater than 40% in at least two seasons between 2008 and 2024 and those who haven’t, we see little difference in the rate of decline by age:

If hard hitters (by my definition) declined faster once they hit that age-32 mark, we’d see a much sharper decline in the red line. That doesn’t seem to be the case here. It looks like hard hitters develop a second wind later in their career versus non-hard hitters. This is important to note because while we can expect players to stop hitting the ball so hard later in their career, it doesn’t mean that a hard hitter who has displayed a power drain will completely fall out of relevance. Adolis García is still projected to hit 28 homers by Steamer.

Don’t want that on your fantasy team? He’s getting too old? Ok. Someone else will take him. It’s just a matter of price. Fantasy baseball typically uses ADP (Average Draft Position) as its price definition. As you enter draft season and you see players like Adolis García, Paul Goldschmidt, and Nolan Arenado fall in ADP, know that the market is discounting their value due to their age, but that projection systems have already accounted for that decline. Know that hard hitters still hit the ball harder than the average in their decline and that passing on 20 home runs is never a good idea.

Here are the players from the table above who are not projected by Steamer to hit above 2024’s MLB average in wOBA and SLG:

• Adam Duvall, DJ LeMahieu, Dylan Moore, Tim Anderson, Austin Slater, Gary Sánchez

For everyone else, a power decline may come, but those players still have fantasy-relevant projections