I was really curious as to what was going on with my eggs because sometimes they came out pointy and sometimes more rounded, from the same chicken! I was always told that the egg should be the same basic shape. I have found that statement is only partly true.
The Answer to the Proverbial Question:
It seems that more pointed eggs are more likely roosters and smoother eggs are more likely pullets or female. I hear that it works better with large breeds and that it is only about a 75% predictor but it is a real help when choosing the eggs you would most like to incubate. Roosters are wanted some of the time and hens or pullets most of the time.
If you have tried this or are going to try this out let me know what your results are. I am going to monitor the ones that I have but they are banty eggs and I hear that it is harder with the banties.
I'll let you know what happens with my pointy one.