as for how they work out the start times: they have tens of thousands of data points (age/sex/estimated time/actual time). It's very there are strong patterns that allow them to work out the actual time the rider is likely to take, which is probably never their estimated time.
What a load of brown smelly stuff.
Lets start with 'actual time'. How can you include that when some may never have done it before, some may have done the shorter distance last year minus two hills and the one who had done it the first year have had two years to progress to a mountain goat or have grown more love handles than all the handles in a tea pot factory. So there are to many unknown variables to RideLondon that make using that pointless.
Now for 'age'. Well, how many of us get passed by older riders? Probably everyone has so age has no bearing.
I'll get the popcorn, 'sex'. Come on then, lets have your explanation on how sex can define someones finishing time?
If that isn't enough for you, lets have an example:
Rider A - A male in his forties who has estimated 6 hours but completed the first RideLondon in 5h30.
Rider B - A female in her early thirties who has estimated 6 hours but completed the second RideLondon in 5h30
Knowing that one rider took their time (no where on the form to say that information), who is the quickest rider? Remember, 'there are strong patterns'
Without the key piece of information, you won't needs tens of thousands of data points so you can't fall back on that
Unless you can show the source of this information, it is all fiction.