I was interested in whether the newly released swing path metrics from Baseball Savant can help us better understand how adaptable a hitter is.

Now that we have the ability to quantify how steep or flat a given hitter’s bat path is using the Swing Path Tilt metric, I used Baseball Savant’s pre-canned strikezone locations to bucket hitter performance against four-seam fastballs in the upper, middle, and lower thirds of the strikezone, limiting pitches to those in the strikezone.

Non four-seam fastball pitch types were excluded to control for the variability of hitter performance against different pitch types, leveling the field. Additionally, I think hitters’ swings against four-seam fastballs, especially those located in the middle third of the strikezone, can give us a good understanding of what a hitter’s baseline swing “signature” looks like, as compared to swings against offspeed and breaking ball pitches.

When looking at a pool of hitters with at least 50 swings against four-seam fastballs in both the upper and middle third of the strikezone during the 2024 season, comparing the differences in Swing Path Tilt and Whiff Rate between the these two vertical zone locations, it was difficult to see any patterns when sorting by the hitters who changed their Swing Path Tilt the most, and the least, between those two zones.

Top 10

Bottom 10

Intuitively we know that steep bat paths can struggle with contact ability against pitches in the upper third of the zone. I then took a closer look at these players specifically (Swing Path Tilt greater than or equal to 36 degrees), comparing above average versus below average differences in Swing Path Tilt of this group using 6 degrees of difference as the cutoff, with ~5.6 degrees being the average tilt difference for this group. Looking at differences of whiff rates (middle whiff minus upper whiff):

Steep path with above-average tilt differential: 6.8% Average Whiff rate differential

Steep path with below-average tilt differential: 13.1% Average Whiff rate differential

Since the metric was released, it’s already been shown that hitter Swing Path Tilt is influenced by pitch location. But by breaking down tilts for steep path specific hitters in this way, we learn that generally a more dramatic swing adjustment is needed for steep-paths to be able to successfully adjust to, and make contact with, high four-seam fastballs.