Were you shooting rapid, or aimed?
there are two schools of thought on this issue.
In combat shooting, the front post provides a more stable sight platform during movement-
-Blurry rear Sight-
-Crisp Front Sight-
-Blurry Target-
But, in aimed precision, all 3 focal points must be constantly adjusted in order to compensate natural body movement. The body does this subconciously, so it isn't like keeping track of 3 wild dogs.