For the first time in 47 years, fans of Major League Baseball get to watch a pair of 100-win teams battle in the World Series.

To borrow a line from Metallica, it’s “sad but true”—the 2017 World Series between the Houston Astros and Los Angeles Dodgers is something MLB doesn’t see too often.

In a sports universe that always is longing to feature the best matchups between the greatest teams, the fact is it hasn’t happened much in Major League Baseball.

The 2017 World Series features two teams that have each won 100 games. How rare is that? Thinking off the top of your head, one would assume that it’s happened many times.

No American sport has had more championship matchups than the World Series. The Stanley Cup is the oldest existing trophy to be awarded to a professional sports franchise, but the “official” Stanley Cup Finals that we know today started in 1926-27 and became the sole property of the NHL starting in 1947. In the NFL, what we know today as the Super Bowl started in January 1967. The NBA Finals officially began in 1950.

The World Series began in 1903 when the Boston Pilgrims faced off against the Pittsburgh Pirates. After a one-year hiatus in 1904 (because John McGraw thought the American League to be inferior to his National League champion New York Giants), the World Series resumed in 1905 and has taken place every season with the exception of the 1994 strike-shortened season.

In the 112 previous World Series that have taken place, only seven times has the Fall Classic featured two 100-win teams Seven times. That’s it. What makes that note even more remarkable is the years in which it happened.

Here is the list:

What makes that list even more incredible is how close these matchups took place. With the exception of the 1931 World Series, each occurrence either happened in consecutive years (1941-42, 1969-70) or one year apart (1910, 1912).

If history means anything, then we can expect another World Series battle between 100-win teams in 2018.

Astros/Dodgers History

What makes this World Series even more unique is that the Dodgers and Astros were in the same division—the National League West—for 25 years from 1969 to 1993.  They’ve met only once in the postseason. That came during 1981’s “split-season,” which was interrupted by a labor stoppage.

Due to the two-month strike, the owners tried to create an equitable solution by splitting the season into two halves, with the first-place teams from each half in each division (or a wild-card team if the same club won both halves) meeting in a best-of-five divisional playoff series. The four survivors would then move on to the two best-of-five League Championship Series. It was the first time that Major League Baseball used a split-season format since 1892.

The Astros and Dodgers met to decide the division. Houston hosted the first two games, while the Dodgers had home-field advantage for the final three (if necessary). After the Astros won the first two games in Houston, both in walk-off fashion, the series moved to Dodger Stadium.

For the Dodgers, facing such an uphill climb against the Astros was nothing new. In 1980, the Dodgers trailed the Astros by three games in the NL West with just three games to play. Those final three games were played at Dodger Stadium against the Astros.

Needing to win all three games to force a one-game playoff, the Dodgers did just that, winning three straight one-run games to force a one-game playoff at Dodger Stadium the next day.

Behind a brilliant six-hit, complete-game performance from Joe Niekro, the Astros defeated the Dodgers 7-1 to reach the postseason for the first time in team history.

Having that history of rallying against the Astros already, the Dodgers were very confident they could repeat their performance from a year ago and finish off the Astros with three straight wins at home. That’s exactly what they did.

The Dodgers pitchers totally shut down the Astros, holding them to just two runs and a .133 batting average for the final three games.

Many things have changed since that 1981 NLDS, but for the baseball historian, it’s always fun to look back and remember when the Astros and Dodgers were once division rivals.

While the Dodgers will be making their 19th World Series appearance, the Astros will be making just their second.

The Dodgers finally made it back to the World Series for the first time since 1988, which most remember for Kirk Gibson’s dramatic pinch-hit home run to win Game 1 against Oakland. The 2017  season marks the 11th time the Dodgers have made the postseason and the fifth NLCS they’ve reached over that span.

A lot has happened since the Dodgers last appeared in the World Series.

• Two teams in their division—the Arizona Diamondbacks and Colorado Rockies—have come into existence. One of them, Arizona (2001), has already won a World Series.
• The Chicago Cubs won the World Series (2016).
• The Miami Marlins came into existence…and won two World Series (1997, 2003).
• The Boston Red Sox and Chicago White Sox both snapped long World Series droughts, with the Dodgers current manager, Dave Roberts, playing a huge part in the Red Sox’s first title.
• The Giants won their first World Series since moving to California…and then their second and third (three titles in five years).
• 22 players currently on the Dodgers 40-man roster were not born yet.
• Wayne Gretzky was beginning his first season with the Los Angeles Kings.
• Kareem-Abdul-Jabbar was starting his final season in the NBA with the Los Angeles Lakers.
• The Raiders were playing in their seventh season in Los Angeles and featured a running back named Bo Jackson who ran for 580 yards in just 10 games in the sport he considered his hobby.

For the Astros, they finally were able to win home games when facing elimination, winning Games 6 and 7 of the ALCS against the New York Yankees. Before then, they had lost their previous five home postseason games when facing elimination.

The Astros pitching held the Yankees to just three runs in their four home games, making the Bronx Bombers just one of two teams—the 1920 Brooklyn Robins are the other—as the only teams in postseason history to score one run or fewer in four road games within a single series.

For the first time in 47 years, fans of Major League Baseball get to watch a pair of 100-win teams’ battle in the World Series. Let’s sit back and enjoy it!