Originally Posted by Hugh Jarse
There was an item in the Aviation Safety Digest quite a few years ago which was written by somebody by the name of Jacobson.
It went through explaining all the maths, etc, and the technique works quite well and consistently.
Jacobson Flare, anybody? 
I can remember doing the bridge to bridge in Perth more than 10 years ago with a TN/QF 737 captain, which gave him enough time to explain to those of us walking with him how he had worked out how to calculate the exact time to flare for any aircraft.
He had documented it and was trying to get it used by QF.
Can't remember if his name was Jacobson though.
He got the idea from an old war movie, not sure which one, could have been "The Dam Busters".