On April 16, 20,000 runners will take to the streets for the 116th annual Boston Marathon. But it will be the last time a 3:10 marathoner can squeak by. In an effort to keep Boston one of the most elite marathons in the country, the Boston Athletic Association, which organizes the event, lowered the qualifying times for the 2013 edition by five minutes—to 3:05 for men 18 to 34. It’s the tenth time the entry standards have been adjusted since 1970, when the BAA first introduced a qualifying requirement (4:00). But faster qualifying times don’t always translate to faster average finishing times: the biggest factor has always been the fickle New England weather.