Millions of people will watch the Women’s College World Series this year. The championship has been a big TV draw for decades, but the softball that draws viewers has little to do with the slow-pitch version played at work outings or church picnics. This is fastpitch, and it is fast—60 feet between bases instead of 90 in baseball speeds up the base-running and fielding; a shorter distance between pitcher and batter also means hitters have less time to react. But the pitching itself is usually the main attraction: Fastpitch softball’s underhand throwing delivery allows for a wide range of hard-to-hit pitches, including some, such as the upward-moving rise ball, that aren’t possible with baseball’s overhand pitching. Pit a professional baseball player against a top fastpitch pitcher, and he’ll most likely strike out, as hitting legends Babe Ruth, Ted Williams, and Mike Piazza all did when they faced fastpitch pitchers at charity events. Fastpitch, at its highest level, is also a sport played almost entirely by women, although this wasn’t always the case.

Softball’s history is long and convoluted. It was invented as an indoor game in Chicago in 1887, several years before basketball and volleyball, America’s most famous homegrown indoor sports, were developed. A group of men had gathered at a local gymnasium to follow the Harvard-Yale Thanksgiving football game via ticker tape; Yale won, and afterward, one of the Yale fans men supposedly celebrated by grabbing a boxing glove off the floor and tossing it in the air, to which one of the other men, a Harvard fan, responded by smacking it down with a broomstick. George Hancock, a sportswriter who was with the group, suggested using the boxing glove and broomstick to play indoor baseball, and the game we now know as softball was born.

Within a few decades, the ball had gotten smaller than its boxing glove-sized namesake, and people were increasingly playing “indoor baseball” outdoors. By 1933, when softball made its official national debut at the Chicago World’s Fair, fastpitch, which featured competitive, hard-to-hit underhand pitching, was the main form of softball. Slowpitch, which involved gently lobbing the ball to batters, existed but was primarily seen as a children’s playground game.

Softball’s status as an amateur sport made it more open to women. At the time, professional sports, such as baseball and football, were viewed as rough activities suitable only for men. Women who wanted to play baseball in the early twentieth century were relegated to traveling entertainment teams that played against men for show and were ridiculed in the press. “In short, the Bloomer Girls [team] knew as much about baseball—professional baseball—as the average man knows about crocheting a peek-a-boo shirt waist, which is less than nothing,” wrote a reporter for Utah’s Ogden Standard after one of the women’s team’s games in 1909.

Fastpitch was a community game, however, which made it more inclusive. The national tournament that began in 1933 featured a women’s category from the outset, and by the end of the 1930s there were women’s fastpitch teams all over the U.S. At a time when hardly any competitive sports were open to women, softball provided a crucial outlet for female athletes. It was also perfectly suited for the Depression, when people had little money to spend on entertainment: the smaller field dimensions, inherited from when it was an indoor game, made it easy for towns to host games at local parks. The games were also shorter, with seven innings to baseball’s nine, which allowed players and fans to fit games around their work schedules.

Fastpitch continued to thrive during World War II and throughout the 1950s. Each year, hundreds of thousands of men’s and women’s teams vied to compete in the national tournament, which attracted huge crowds and awarded trophies that were often as tall as the players. It wasn’t unusual to see softball covered in newspaper sports sections alongside professional baseball. But, as an amateur sport that wasn’t in the Olympics, fastpitch didn’t offer much in the way of career prospects, and men gradually started leaving the game. Those who wanted to be professional athletes had baseball and an array of other sports to choose from, and men who were more interested in playing softball recreationally began switching to slowpitch.

Unlike fastpitch, slowpitch requires hardly any training or practice. It’s more akin to miniature golf or broomball; there may be some who take it seriously, but it’s meant to be played for fun. The ball is lightly tossed to the batter, and home runs are so common that the rules penalize teams for hitting too many (three to ten, depending on the league)—otherwise some of the games might go on forever. It was a sport that could be played while drinking a beer, hence the emergence of so-called beer leagues in the 1970s.

By the 1980s, the knucklehead antics of beer league slowpitch (for an example, see this 1983 Miller Lite commercial featuring Rodney Dangerfield as the pitcher) had come to represent softball to many, if not most, Americans. Fastpitch, meanwhile, was evolving into a sport played almost exclusively by female college students. Men could afford to give up fastpitch for the silliness of slowpitch because they still had baseball—women didn’t have that option.

“I won’t have a girl playing for me. This is no-woman’s land, and believe me I mean it,” a minor league manager told the press in 1952 after it was announced that a woman was going to be joining his team that summer. (The female player was dismissed without ever playing a game, and soon afterward women were officially banned from playing professional baseball, a ruling that stood until the 1990s.

As a result, women had no choice but to stick with fastpitch. Then, after Title IX passed in 1972, colleges adopted the sport as the female equivalent of baseball. Had they not, it’s possible fastpitch would have died out completely by the late 1980s. Instead, college softball took over where amateur adult teams from the 50s and 60s left off and paved the way for fastpitch to enter the Olympics. There’s also a professional women’s softball league, National Pro Fastpitch, that players can join after they graduate.

When men still played fastpitch, the sport was recognized as a baseball alternative—different, but not inferior. Now that fastpitch is thought of as a women’s game, however, there are assumptions that it’s easier, and therefore lesser than baseball. The nomenclature of softball can also be problematic. At the college level, fastpitch is simply referred to as “softball,” but the college softball coaching association and the professional women’s league both use “fastpitch” in their names, implying a difference when there is none. In 1993, UCLA pitcher and future Olympic gold medalist Lisa Fernandez recalled being asked by an airport employee if her college team played slowpitch or fastpitch. “It’s 1993, and people still think we’re playing slowpitch,” she lamented.

Making matters even more confusing, some high school and college softball teams were playing slowpitch in the 1990s, particularly in the Southeastern U.S., because the coaches, most of whom were men, had no experience with fastpitch. “We’re going to look like fools if they just throw it at us…No one has ever played it,” one Florida coach worried. It took lawsuits by students’ parents to finally get the schools to change.

Today, girls all over the U.S. can play fastpitch, often starting as young as four years old. The sport’s addition to the Summer Olympics in 1996 had a lot to do with that, as did ESPN’s extensive coverage of the college tournament, which started in the 90s. Softball is probably the most visible women’s college team sport besides basketball, and it’s still growing. States that only offered slowpitch twenty years ago now boast some of the most competitive fastpitch teams in the country: five of the eight teams that played in the college tournament this past weekend were from the South. Teams from schools in the Northeast and the Midwest are also getting stronger, and the sport continues to attract new fans in those regions.

That doesn’t mean slowpitch is going away, but its tenure as the best-known form of softball may be ending soon. There’s a strong chance that fastpitch will be back in the Summer Olympics in 2020, after being voted off the program in 2005. The increased media exposure that will bring, combined with the growing popularity of the college game, could be the boost fastpitch needs to become not just familiar but appreciated as a complex, difficult sport—the golf to slowpitch’s mini-golf. Then maybe fastpitch players won’t constantly feel they have to explain their sport to people, and they’ll be respected for the highly-skilled athletes they are.