But Wednesday, after an 820 game streak unprecedented in major professional sports, that epic streak came to an end.
The official attendance for Wednesday's loss against the Baltimore Orioles was 30,862, well short of the 37,499 night game capacity at Fenway Park.
It was an end the Red Sox saw coming.
Anticipating soft demand for ticket sales after a heartbreaking collapse at the end of the 2011 season, and last-place performance in 2012, the Fenway brass tried to lure fans back to the stadium with deals on hot dogs, beer, and food for kids.
And though the team, with a new manager at the helm for the second time in as many years and plenty of long-time favorite players shipped off to other franchises, is off to a good start, the fans have been slow to forgive.
Before the Red Sox embarked on their 794 regular and 26 postseason sellouts on May 15, 2003, the previous Major League Baseball record was held by the Cleveland Indians, who sold out Progressive Field for 455 consecutive home games between 1995 and 2001.
The NBA's Portland Trailblazers held the former record in all sports with an 814-game sellout.
"We are proud of this historic achievement," said Red Sox President/CEO Larry Lucchino in a statement released by the team. "Over the past ten years, more than 30 million, many among the most sophisticated baseball fans in America, have purchased tickets to see games at Fenway Park.
"Never in that period was there a crowd less than 32,000. No other club in Major League Baseball can make that statement. That speaks volumes about the constancy and dedication of New England baseball fans."
In 2012, when the record-breaking game approached, the Red Sox official accounting came under fire when a report revealed that the team (and for that matter, most professional sports) use a less-than-literal definition of "sold out."
"The Sox count the total number of tickets they distribute, including an average of 800 complimentary tickets each game to charities and others, as the basis for a sellout," the Boston Globe reported. "They also count standing room tickets toward the total."
(Standing room tickets still cost between $20 and $35 each, plus fees.)
Red Sox Executive Vice President Sam Kennedy defended the streak at the time, explaining that Boston gives away far fewer tickets than most teams.
Still, the Red Sox shouldn't worry. Boston's obsessive fan base stuck with them for an 86-year "cursed" World Series drought, although not coincidentally, they broke that curse in 2004, in the second season of the streak.
It's too early to read anything into the Sox's first-place start, but if the team plays well, 2013 could be the start of the next big sellout streak.