Some basic research. It seems very hard to sit 96+ and have a stuff+ below 90 on a 4 seamer (there is basically nobody) but once you get closer to 95 with the sitting velo it is possible
Examples:
Brent Honeywell, 95 mph, 71 stuff+
Charlie Morton, 95 mph, 74 stuff+
Chris Martin, 95.9 mph, 90 stuff+
Johan Oviedo, 95.8 mph, 83 stuff+
Logan Gilbert, 95.8 mph, 88 stuff+
Sam Hentges, 95.7 mph, 77 stuff+
Jon Gray, 95.7 mph, 82 stuff+
Just a big difference between sitting 96.5 and 95.5.
So, some 96 mph fastballs on WBC video is meaningless. A stuff+ rating of 75 is completely possible if he sits 95 or so with really bad shape.
In the 96+ average mph bucket, there is basically nobody sub 90 stuff+ and only a few guys below 100.
The twitter reference from the secondary source with a 100 "stuff" rating is not the same measurement, it is some wStuff metric I have never heard of. I kind of trust Eno's stray tweet more tbh.
Looking to see this guy working on cutters and power sinkers in spring.