Doc...the obvious error is when the speaker is trying to teach in his clinic how he sets his ten foot limit by setting what i will call a horizon mark.. He referenced he sets his ten feet with a tree of something out there..meaning out of the field of play.
The error in doing what this ump says he does is...the zenith of a pitched ball varies with where the ball was released in accordance the the pitching rules..and the height/speed of the release.
Using the conference fixed (frozen) rubber rule...the pitcher can stand behind the rubber releasing a ball from approx. 51 feet...or in front of the rubber releasing to the plate approx. 46 feet)... that creates a huge variable as to the horizon vision point the speaker referenced. why? because those variables invalidate the the umpires site lines.
if this umpire was teaching umpires on how to set heights when the floating rubber is in effect...it’s even worse..using the floating rubber the pitch can be released from approx. 57 feet or 46 feet. every pitch has a very different horizon 10 foot height point of reference.
this umpire referrers to graphics and pages in the rule book so i have to guess this is a serious umpire teaching session.
I think he does a great job on most everything...it’s just his concept of setting his ten foot limit is way off base. now if he said he set that “tree/whatever” he refers to at fifty feet and then watching the pitch release depth from his fixed umpire vision point and adjusts accordingly...he is heading in the right direction.
ie...the ten foot point is higher then the “tree” when the ball is pitched from in front of the rubber and lower when released from behind the rubber... maybe if he is tidying this so much he knows rule page numbers and graphics... he could add a graphic sharing how horizon vision points change with distance of point of release