Yes, I'm going to flog the subject of glaze fit one more time. Conversely, a poor fitting glaze can cut it to one third of unglazed strength. Incredibly, this range can occur without any visible difference in an otherwise attractive glaze, not even crazing. Many potters and technicians just do not want to know if there is a serious problem with their glaze. I am assuming you, however, would like to optimize things.
Awareness is a good place to begin.
Let's form a model to help us understand things better. Since clay and glaze have to live attached to each other, they must expand and contract together. A poor fitting glaze expands at a different rate than the clay to which it is attached. Usually there is no visible indication that there is a glaze fit problem, especially if the two are joined or interfaced well. But beneath that beautiful exterior, tension may threaten continued survival of the piece.