Washington Nationals left fielder Juan Soto knocks in two runs with a double Tuesday during the Washington Nationals defeat of the Houston Astros in Game 1 of the World Series. Players like Soto and dramatic moments help make a World Series one that people will remember. (John McDonnell/The Washington Post)

The Washington Nationals are in the World Series!

The Nats on Tuesday won the first game, 5-4, of the best-of-seven series as left fielder Juan Soto drove in three runs.

The World Series has been played almost every year since the professional baseball championship began in 1903. There was no World Series in 1904 because New York manager John McGraw would not allow his National League champion Giants to play the American League’s Boston Americans. In the fall of 1994, all players were on strike — refusing to play until they agreed to a new contract with the team owners.

This World Series between the Nats and the Houston Astros is the 115th Fall Classic. Some World Series have been more exciting than others. Let’s look at what makes a great World Series.

Seven games: Nothing is more exciting than a single game and it’s winner-take-all. Thirty-eight of the World Series have gone the full seven games.

In 2016, the Chicago Cubs won the seventh and deciding game against the Cleveland Indians, 8-7 in extra innings. The Astros beat the Dodgers in seven games in 2017. So it can happen. And when it does, it’s baseball heaven.

Houston Astros’ José Altuve, left, celebrates with teammate Yuli Gurriel after two first-inning runs during Game 1 of the World Series. Altuve is one of the most exciting players to watch. (Toni L. Sandys/The Washington Post)

Great players: It’s a thrill to watch top athletes playing on their game’s biggest stage. In 1975, the Cincinnati Reds beat the Boston Red Sox in seven games in maybe the most thrilling World Series of all (it included five one-run victories).

Each team featured three future Hall of Famers. The Red Sox had Carl Yastrzemski, Carlton Fisk and Jim Rice. The Reds had Joe Morgan, Johnny Bench and Tony Perez.

The Reds also had the all-time leader in base hits: Pete Rose. (Rose is not eligible for the Hall of Fame because he gambled on baseball games.)

Washington fans know the Nats have plenty of top-flight talent, such as third baseman and NL Most Valuable Player candidate Anthony Rendon as well as Soto, a phenom who turns 21 years old on Friday.

The Astros are loaded, too. Second baseman Jos é Altuve is listed at only 5 feet 6 inches tall, but he is a six-time all-star and a big-time player. Third baseman Alex Bregman may have had a better year than Rendon.

Nationals starting pitcher Max Scherzer, center, is congratulated in the dugout after pitching five innings during Game 1. The Nationals’ and Astros’ starting pitchers are some of the best in baseball. (John McDonnell/The Washington Post)

Great pitchers: The teams’ starting pitchers are the biggest stars. The Nationals’ top three — Max Scherzer, Stephen Strasburg and Patrick Corbin — posted a stellar combined record of 43-20 (43 wins and 20 losses) during the regular season.

The Astros’ three top starters were even better. Justin Verlander, Gerrit Cole and Zack Greinke were a combined 59-16.

Dramatic moments: The last time a Washington team won the World Series was in 1924 when Hall of Famer Walter Johnson came out of the bullpen to pitch the last four innings and win the seventh game, 4-3, in 12 innings.

Imagine if Scherzer or Strasburg did that for the Nationals! Fans would talk about that World Series moment for a long time to come.