gun or chip time to win

The problem, groovy, lies solely within your failure to recognise that it's UKA or equivalent book that matters, not groovy's for reasons clearly argued all over this thread.

There just isn't an element of opinion in determining the winner, unless in very unusual situations (gun vs chip time definately not being one of them).

The finishing order is the order across the line.

People asked for Chip times so that they could get an accurate time of how long it took them to win a race due to the large numbers in some. You can't campaign for that and then wha the results by it. Chip timing was resisted for some time for exactly this reason.

 You have to place yourself in a reasonsable position for what you are likely to achieve. I run a Grand Prix series i nthe spring and I do tend to place myself slghtly nearer the front to avoid somebody beating me by a few seconds just because they were ahead.

If we feel we can't get close enough to the front then are we arguing for races t ohave wider starts and smaller numbers? Say 300 max.

 In the 100M final at the Olympics the first across the line wins. They don;t have a mat after one metre and say don't worry if you get a slow start we'll only start timing once you are into your running and the fastest time wins. They also have a limit of 8 runners to accommodate.

 Lets be honest here though, most people aren't that worried about places if you are 501 or 503 doesn't make much difference, unless you are a front runner who might win a prixe. In that case you start at the front.

Gun time for me but  what about, for example, Bristol Half that has 2  distinct waves. At the finish there is a separate clock with the times for each wave. Unlikely, but someone could be "win" the second wave in a quicker time than that of the first wave. Could argue that if you get put into wave 2 you can never win the race and it is therefore only a time trial

How do Musky - long time no see.  In your example, those with a chance of placing would be in the first couple of rows of the first wave. 

Last time I did the Great South, they had 3 waves, effectively making it 3 seperate races.  They didn't award prizes for the winners of each wave as the elites set off on the first wave.

That is an interesting example but it also relates back to the original scenario, in that someone who has managed to conspire to run the fastest time without crossing the line first has basically mugged themselves off!  As BDB states, if you think you have any chance of winning even an age category prize for the Bristol HM you will be in the first wave.  It is certainly physically possible for someone to be placed in the second wave but to run faster than prize winners in the first wave, but by placing themselves in the second wave they have literally put themselves out of the running to begin with.