The Houston Astros won the first World Series in franchise history in 2017. The last thing the team did was get complacent. In the offseason, they went out and added Gerrit Cole to form one of the best pitching staffs in the entire league.
At the trade deadline, they stayed active and pursued improvement. The Astros traded for Ryan Pressly, Martin Maldonado, and Roberto Osuna. All three of these guys played a key role in the last couple of months of the season and in the playoffs. All of this led to the best regular season in team history with 103 wins.