I got my 5th rejection in a row yesterday, I last ran it in 1994 & really fancied another crack at it but unless I can get a club place (a possibilty) I won't be doing it again, I'll find another one. I really don't believe it's 1 in 4 chance of getting in, the ballot stopped at 160,000, they accept close to 40,000. This figure doesn't include all of the thousands of charity places, I would love to know what the real chances of getting in via the ballot are.
The actual statistics are never made public, but the most reasonable "best guess" I've seen is that out of a total of about 45,000 there's 20,000 ballot places, 12,500 charity places, and the rest for last year's dropouts, five-strikes, overseas entrants, championships, gfas,etc. The ballot closed at 125,000 so the chances of success is approx 1 in 6.
Unfortunately statistics count for nothing in the computer age because it is generally accepted that the organisers "shape" the ballot to give the distribution of finishing times they want. The optimum time to put on your application been debated on these forums for years, with no satisfactory conclusion. However I'd bet that they want the majority to finish around 4-5 hours while the live TV coverage is still on. They don't want a huge number of over-60's (my category) coming in at 7+ hours while they're trying to wind down their operation in the Mall!
I think you might find a large number of older runners will still finish in a good time. I will be over 60 but still hope to push close to 3.30, and there will be a lot of over 60s faster than that.
In general I think it is the first time and real fun runners who occupy those later slots.