Arm Strenght And Blocking

[DOneSports_PSN]

How do they determine the following attributes:

Arm Strenght for position players and
Blocking for catchers?

It's the only informations that is not available at MLB Savant.Thanks.

[broken_toy1_PSN]

Blocking for catchers would probably be based on passed balls. Arm strength would probably be some metric most people don't look at, but statistic lovers keep. Probably something based off of opportunities to assist ratio and speed of throw. A short stop recently threw a ball to first at over 100mph to complete an assist.