For tens of thousands of Boston runners, Marathon Monday is the pinnacle of months and sometimes years of training, on top of strict qualifying times and guidelines.

But with an ever-increasing number of runners, it’s getting harder and harder to make the cut — even if you’ve made the qualifying time.

According to author, journalist and 1968 Boston Marathon champion Amby Burfoot, Boston is too strict for its own good. “I believe Boston, with current technologies and wave starts and whatnot can even accept more runners than they’re letting in now,” Burfoot told Boston Public Radio on Monday. “If there’s a universal gripe, it’s the fact that Boston has a qualifying time, but if you reach the qualifying time, you don’t necessarily get in the race anymore.”

The Boston Marathon is one of a few races that maintains strict qualifying times and requirements that only grow more stringent every year. This year, the Boston Athletic Association received 26,171 applications before the September deadline to apply. Of those registered, 2,957 were kicked off the list. Boston’s 2017 qualifying times range from 3:05 for men age 18 to 24 and 3:35 for women. If you are 80 or over, the qualifying time is 4:55 for men and 5:25:00 for women.

“A little bit less than ten percent of the running population can hit those qualifying times,” Burfoot said. Even then, the rules can change even after the times have already been established. “In recent years, people have qualified but not gotten accepted by the race because they took a couple of extra minutes ex post facto off the qualifying time,” he said.

With those odds, a runner’s best bet might be to run for charity. “There’s an ambivalence among many of us,” Burfoot said, “[but] the work that these people do and the charity fundraising is incredible, and I stand in awe of that.”

To hear Amby Burfoot’s full interview with Boston Public Radio, click on the audio link above.