As the Philadelphia Phillies will tell you, when the Nationals’ Stephen Strasburg is pitching well, he’s hard to beat. (Toni L. Sandys/The Washington Post)

The Washington Nationals have a big series with the Atlanta Braves this weekend. The three games might have a lot to say about which team wins the National League East Division.

The major-league baseball season is long — maybe too long. Each team plays 162 games. The season starts with the promise of spring, drags on through the dog days of summer and ends in the chill of October.

Games won early in the season count just as much as games won in the heat of a pennant race. Still, some games mean more than others. Such as whenever the Nats play the Braves.

Washington and Atlanta have been locked in a battle for first place all season. After Tuesday’s games, the Nats had a three-game lead over the Braves. Atlanta has been struggling lately, but the team is not out of it.

That’s why this weekend’s games are so important. If the Nats could win two of the three games or even (fingers crossed) sweep the series, they would open up a sizable lead with fewer than 50 games to play in the regular season. But if the Braves win or sweep the series, they are right back in the race.

I think the Nats are the better team, but for some reason they have problems with the Braves. This season, they have won three games against Atlanta and lost seven. That’s a 3-7 record. In 2013, the Nats record against the Braves was 6-13. Not good.

The most important player in any single baseball game is the starting pitcher. If he pitches well, you have a chance. So let’s look at the Nats’ starters in the series.

Stephen Strasburg is coming off one of his best games of the season. The Nats fireballer shut out the Phillies for seven innings Sunday while striking out 10 batters. Hopefully, he will have the same ace stuff on Friday night.

Tanner Roark has been a wonderful surprise this season. The 27-year-old right-hander has won 11 games. Maybe he can surprise the Braves on Saturday.

Roark is a great lesson for kids. Drafted in the 25th round of the 2008 major-league draft, he seemed stuck in the minor leagues. In 2012, his record for the Syracuse Chiefs was 6-17. But Roark did not give up. He kept working, got better and now is a solid major leaguer.

Gio Gonzalez has been up and down this season. Who will show up for Sunday night’s featured game on ESPN: the good Gio or the bad Gio?

The Nats have a good chance to win the East Division and make the playoffs. But first they have to learn to beat the Braves.

Starting this weekend.

Bowen writes the sports opinion column for KidsPost. He is the author of 19 sports books for kids, including nine baseball books. His 20th book, “Double Reverse,” will be published this month.