Part of the charm of Marin’s Dipsea is that a runner from 1905, the year of the first Race, would find his way from Mill Valley to Stinson Beach largely unchanged.

Yes, there have been shifts. There are a lot more trees since the dairy ranches along the route departed. There are far more entrants, so many that the field is now (since 1977) split into two sections. And many of these runners (since 1971) are women.

But the biggest change, by far, is that made in 1965, in the way head starts are assigned. So 2025 marks the halfway point over the Dipsea’s 120-year history for that seismic revolution.

The Dipsea has always been a handicap race, with runners judged slowest sent off ahead of speedier entrants. These assessments were made by the Race handicapper, or a small committee, who knew most every entrant in the days when the running community was small. The head start, or handicap, originally ranged from zero (called “scratch”) to 12 minutes. That maximum varied over the years, sometimes lower, often higher (the current maximum is 25 minutes). The handicaps are now always in full minutes, but once not.

The essential point of the original, individually assigned head starts was that every single starter, save a handful too slow even with the maximum award, felt they had a chance to win. And newspaper reports of the results — the Dipsea was regularly covered by all major San Francisco dailies — frequently used terms such as “dark horse” and “practically unknown” in describing winners with large head starts. Tennis star Phil Smith won in 1961 in his very first race of any kind!

Invariably, there would be griping that the winner’s handicap had been too generous. There was even talk that some runners deliberately ran poorly the previous Dipsea to increase their head start. In any case, Dipsea winners would then forever have their handicaps slashed so drastically there was not a single back-to-back winner for 66 years.

In the early 1960s, partly spurred by President Kennedy’s fitness initiatives, a national running boom began exploding. In 1962, there had been 61 Dipsea finishers. That number doubled in ’63 and rose to 169 in ’64, many signing up Race morning (no longer allowed). It wasn’t feasible for the handicapper to know each runner, many complete novices. There was also some odd handicapping, such as in ’62 to help scratch runner Pete McArdle (who did win) and in ’64, when head starts were so generous scratch runners had zero chance for victory.

So the Mill Valley Junior Chamber of Commerce, which inherited management of the Dipsea in 1963 from the San Francisco-based South of Market Boys, initiated a monumental change. The prime mover was Jerry Hauke, who would remain the Dipsea’s towering Race director for decades.

Starting in 1965, head starts for all 214 entrants became entirely based on age. The initial effort was crude; the top three finishers, all seniors, each had 15-minute head starts while the following 12 all started scratch. The next year, 10 of the first 13 finishers (including winner Carl Jensen) were scratch; Jensen remains the Dipsea’s last scratch champion. In ’67, all the top ten save the winner (Jack Kirk) had zero handicap.

Then Jim Weill, an MIT-trained statistics and horse racing buff, took over as handicapper, a position he held for 50 years. Head starts became so refined that griping about them — a tradition as old as the Dipsea — almost disappeared. In 1971, Weill accommodated the arrival of women as official entrants, with head starts now also reflecting gender. In 1986, in response to Sal Vasquez’s dominance (seven victories), Weill began saddling recent winners with penalty minutes.

The shift to formulaic, rather than individual, handicapping was huge, fundamentally changing the Race. From 1965, forever forward, not every starter thought they had a chance to win. In fact, now only about one percent (of the 700 Invitational starters) feel they have a realistic shot at victory, with perhaps an additional one percent hoping for a miracle.

There’s been some talk of returning to individual handicapping, perhaps for the top 25, 50 or 100 entrants. It remains just talk. So for now, to get more head start minutes, you must, like they used to say about the old Brooklyn Dodgers, “Wait until next year.”