All runner-types know the two most famous marathons in the world: the Boston Marathon, and the New York City Marathon. They're not famous for their gorgeous views, downhills, or volunteers - it's all about entry rules.
Boston is the oldest marathon on the planet and in its early days attracted such an elbow-throwing crush of runners that they had to come up with restrictive entry rules as a way to cap the field. You have to qualify to run Boston by meeting speed requirements in your age group - pretty effective. Boston's assured that not a single person running the marathon is a newb; no amateur, 5-hour, sluggish, back-of-the-packers run Boston. The race is SO competitive now that all the spots allotted are usually snapped up and sold out in a ridiculously small window of time. Check this crazy stat from wiki about this year's race: 'on October 18, 2010, the 20,000 spots reserved for qualifiers were filled in a record-setting eight hours and three minutes.'
Ho Lee Shit.
New York is a bit different - they cap the enormous numbers attracted to the race by having a lottery, and sending the racers out in a couple of waves. How many run New York? Almost fifty-thousand. If you register for NYC but you don't earn a spot in the lottery, you're differed to try again. If after three years your luck STILL stinks, they reserve a spot for you automatically, because, geez, you've really been trying, haven't you?
In case you're wondering - my best time is 3:53. The time I'd have to make to run Boston? 3:40 and 59 seconds.
I know, that's only 12 minutes, right?
On race day, that's an eternity.
New York City 2010 happened on the 7th - here's this year's pack in time lapse.