Bases Loaded is the first installment of the Bases Loaded series, followed by seven sequels across three generations of consoles. There are three more video games in the Bases Loaded NES series, Bases Loaded II: Second Season, Bases Loaded 3 and Bases Loaded 4. There was also a Game Boy version of Bases Loaded. The series continued onto the SNES platform with Super Bases Loaded, Super Bases Loaded 2, and Super Bases Loaded 3. The final entry to the series was Bases Loaded '96: Double Header, released for the Sega Saturn and PlayStation.
Bases Loaded is also the first in a series of eight sports Famicom games known in Japan as "Moero!!". This series is all generic sports games. Three of the games were localized in the Western Markets as Bases Loaded, Bases Loaded 2, and Bases Loaded 3, and the basketball game as Hoops. Four titles went unreleased stateside or in the Pal regions..
These eight games, by release date, are as follows: Moero!! Pro Yakyuu (Red) (Bases Loaded), Moero!! Pro Tennis (Racket Attack), Moero!! Pro Yakyuu '88 - Kettei Ban (Bases Loaded II: Second Season), Moero!! Junior Basket - Two on Two (Hoops), Moero!! Pro Soccer (Japan Only), Moero!! Shin Moero!! Pro Yakyuu, Moero!! Juudou Warriors (Japan only), and Moero!! Pro Yakyuu '90 Kandouhen (US Bases Loaded 3).
Source: Wikipedia, "Bases Loaded (video game)", available under the CC-BY-SA License.