Why Do MLB BU's point foul...

[lawump]

As taught at umpire school and PBUC camp in 1997:

An umpire's order of priorities in calling a play are:

(1) Fair/Foul
(2) Catch/No-Catch
(3) Safe/Out (on bases)
(4) Other plays

In otherwords, pro umpires are taught to always point fair or foul FIRST. Then, SECOND, they signal catch/No-catch. However, it is perfectly acceptable (in fact it was taught) to make NO catch signal if the catch is made cleanly by the fielder above his belt.

PDX pretty much hit on the head as to why the Fair/Foul is signaled first.