The Mendoza Line

Wednesday 12/16/09

Lou Marcelli is the grizzled eminence grise of the Dolphin Club. Actor, chef, and club commodore, Mr. Marcelli maintains a disciplined year-round swimming schedule. As an avid baseball fan and keen observer of Bay water temperatures, he was the first to appropriate the phrase “Mendoza Line.”

Shortstop Mario Mendoza has long been known for setting the major league standard for beggarly batting average. Baseball players who strike the ball successfully one out of three times enjoy outsize acclaim and riches. A lifetime batting average of .333 is among the performance statistics that will trigger candidacy for the Baseball Hall of Fame. In fact, anything at or near the .300 mark qualifies as a remarkable hitting career.

George Brett, with a lifetime batting average of .305, is apocryphally credited with saddling Mr. Mendoza with his unfortunate distinction. The term applies to a player who fails to safely strike the ball in two out of ten plate appearances. As such, anyone failing to hit at least .200 is “below the Mendoza Line.” As with other colloquial phrases the origins of this one are in some dispute. Some historians theorize that years ago, when the Sunday papers didn’t report all batting averages, Mario Mendoza provided the demarcation below which this statistic was absent. Others suggest that this is a reference to failing to “hit your weight,” when a ballplayer’s batting average is less than his body weight in pounds. In this case, the Mendoza line fluctuates.

As it relates to the Bay, the Mendoza line doesn’t fluctuate. When the water chills to below 50 degrees, the line is breached. For Dolphins who are aware of this boundary, it takes a spectral form. As the temperature nears 50, Mendoza is sighted descending from Mt. Tamalpais. At 50, Mendoza is knocking on the door. When the temperature cracks the south side of 50, Mendoza takes up residence at the Oprah buoy. When the temperature remains below 50 for several days or weeks, Mendoza and his extended family are camped in a freezing caravan at the Oprah, toasting marshmallows, and singing “Let it Snow.”

Most Dolphins will agree to four general categories of Bay water temperature. Above 60 degrees is “balmy.” Between 55 and 60 is “brisk.” Between 50 and 55 is “cold.” Below the Mendoza line, it’s “f***ing freezing.”

Regarding the latter category, the betting usually revolves around whether Mendoza will arrive in time for the New Year’s Day Alcatraz swim. This year, the plunging thermometer has the smart money riding on his appearance before the Polar Bear starts on December 21st. Odds are currently at 5:1 and my money’s on Mendoza.


  1. I always wondered what Lou was talking about. Thanks for explaining this. But did you have to remind us???

  2. Do you know if any controlled research has been done on Aquatic Park swimmers that proves - or at least suggests - that cold-water swimming has made them healthier or physically stronger? That is, if Person A regularly swims in a pool for 5 years averaging 3 workouts a week (1 hour per session) and then swam in Aquatic Park with the same frequency over the same period of time (swimming up to 1 hour per session), can research prove - or suggest - that the physical results of cold-water swimming is relatively better for an average adult? If not, how could such a study be conducted? I would be very interested in the results, methodology and conclusions of such a study.