Radar to most means....."Is he throwing 90?"......."Is he impressing everyone?"
To me it means......"Is he throwing what he's capable of"...."How far off is he?"...."What do we need to do to get him to his potential?"
A huge difference.
I guarantee you don't know a 2-5 mph differential by sight.
Therefore, you don't know whether a pitcher is throwing his velocity potential or not.
Therefore, you may not know when a pitcher needs mechanical work.
Of course, most of you think it's some kind of magic anyway.
A radar gun will tell you very important feedback information.