I wanted to post one more graph from trying Tango's delta method. Contact has a much later peak than swing speed and chase. I'm looking at a bunch more articles on aging curves, would love to see any others people have!

Reply here if you want the report for another catcher's Cape or NCAA season!

5. Easton Carmichael @3aston_11 @OU_Baseball @YD_RedSox

4. Ryder Helfrick, 17 G, 1.64 SLAA/G @HelfrickRyder @RazorbackBSB @BrewsterCaps

3. Manny Garza, 7 G, 1.69 SLAA/G @emmanuelgarza34 @ASU_Baseball @harborhawks

2. Talmadge LeCroy, 6 G, 2.14 SLAA/G @TalmadgeLeCroy @GamecockBasebll @YD_RedSox

1. Bryan Arendt, 4 Games, 4.91 SLAA/G @bryan_arendt6 @UNCWBaseball @HarwichMariners

🧵My Top 5 Framing Catchers in the Cape League this season (measured by SLAA/G, min. 2 games). Read more about my approach at

As a final note, I'm looking to learn more about how to coach catcher defense. At the moment I can show statistics, but not the mechanical adjustments for actual improvement. Any Twitter follows, books, videos, articles, etc. would be appreciated! 19/END

I used @nickwan‘s code on Kaggle to visualize the Strike Zone and Shadow Zone, so I appreciate that greatly as a resource! Also wanted to thank @Tjstats and @UmpScorecards for being inspirations for the tidy, impactful reports they make. All data from @TrackmanBB 18/

Just like my last project, thanks to all the other analytics interns @BeilkeAidan3 @gabe_appelbaum @RichyLegs13 @mlbalchemist . I also learned a lot from @tcoz_2 and his college catching experience. 17/

Now that you know the process, I’ll soon have an article and thread up about the best defensive catchers on the Cape this summer. For now, comment here if you want to see the report for your favorite player! @Codball 16/

I’ll definitely be extending Catcher Reports to this upcoming NCAA season, as the Trackman data will all be the same format. The model training and comparison will be different, because I can’t rely on umpire consistency across conferences, but things should stay similar. 15/

Both Cannon (@Vol_Baseball) and Jaxson (@FSUBaseball) finished the season with above average framing numbers, and I’m very excited to see them catch for their schools this year. 14/

Our catchers @cpeebs34 and @Jaxsonwest8 both had really strong work ethic to sharpen their catcher defense. I showed the reports to both of them at different points of the season, and the SLAA heatmap seemed like the most helpful part to identify areas for practice. 13/

To format all of these elements into PDF form, I used a Python package called FPDF. It took plenty of trial and error to position and scale things, but I eventually put everything in place. Here’s a report for a single game, and one for a full season (which measures SLAA/G). 12/

Unfortunately, Trackman doesn’t track passed balls and blocks, so I wasn’t able to put that into the report. If I end up creating MLB Catcher Reports, I can do that with StatCast. That’s a future goal for sure, maybe even a Twitter bot! 11/

This captured the framing aspect, so I then moved on to the running game. For each game, the catcher would have every stolen base attempt, their throw location and their throw metrics. In the season-long mode, the metrics were averages rather than individual throws. 10/

I also put a table split by pitch type on the report, in case the data shows they might have more difficulty with certain pitches. For each type of pitch, the report shows the amount of Shadow Zone pitches (essentially the outer fringe of the Strike Zone) called strikes. 9/

But telling a catcher their percentile rank doesn’t really mean much– I wanted to show them how they could improve. So I converted the SLAA into a heatmap, where they could see which areas of the Strike Zone they were struggling in and could practice more. 8/