Over the past three seasons, the Chicago Cubs and Houston Astros have combined for a record of 376-596 (.387 winning percentage) and have become known as two of the least successful franchises in the sport. Behind the scenes during those three seasons, though, these two teams have been working to build a contender. All of that losing and behind-the-scenes work has finally paid off.

Even in the midst of their longest losing streak of the season, the Cubs are 39-35 and in the National League Wild Card chase while the Astros are in first place in the American League West with a record of 44-34. Though neither is a favorite to win their respective leagues, this progress is a sign of bigger things to come.

Each team has built an impressive core of young players who figure to contribute to the team’s success now and in the future.

Here are the respective cores of young players for each team:

Cubs: Addison Russell, Starlin Castro, Javier Baez, Anthony Rizzo, Kris Bryant, Kyle Schwarber and others.

Astros: Jose Altuve, George Springer, Jon Singleton, Carlos Correa, Dallas Keuchel and others.

The fact that all of these players are so young and under team control for the foreseeable future makes these teams contenders from 2015 into the next several seasons. Having these young players at a relatively low cost (since they’re either on rookie deals or team-friendly deals) also makes each team capable of adding proven veterans via trade and free agency.

That is apparent with the Astros being connected to top trade deadline target Johnny Cueto and the Cubs’ ability to sign a top free agent pitcher this offseason like Jordan Zimmermann, David Price or others.

With these respective cores and the ability to add players in problem areas, the Cubs and Astros are going to be serious contenders for a very long time. In the next five seasons, each of these teams should win a World Series. They’re simply well-equipped to play deep into October, possibly starting this season.

These two teams that fans have gotten used to seeing at the bottom of their divisions are ready to win, and they’ve already shown that this season. Fans better get used to seeing them in October, because with the way each of these teams is constructed, anything less than a World Series title for each in the next five years would be a disappointment.