Doesn't temperature control to an extent?

Yea Yea, boiling water 100°C at NTP**. But........

1) normal mercury on the barometer (variable)
2) Above Sea Level (consistent)
3) temperature profile
    a) eggs out of the fridge, consistently?
    b) water temp at the start of the cooking. ie start at (say) 50°C from the tap.
4) how consistent are the eggs?
    a) hen,
    b) age plus storage at the shop (very variable)
    c) size
5) time
6) more experimentation.
7) Let us know, when you become an............... eggspert.
8) I'll get my coat.

**Normal Temperature & Pressure