Out of the Park Baseball was born in 1998, when lead developer Markus Heinsohn had the vision to combine a highly realistic baseball simulation with career play. His goal was to create a game that allowed users to run a virtual baseball franchise. With realistic statistical output, the game was satisfying to hardcore baseball fans and casual gamers alike.

The first version was released in May 1999, with the help of Sean Lahman, who sold the game through his website. The initial version of the game was very promising and received outstanding ratings from several online gaming sites.

That same year, Steve Kuffrey teamed up with Markus Heinsohn after Sean Lahman changed jobs, and both worked together to develop the second version of Out of the Park Baseball, which had become known simply as OOTP within the growing game community. OOTP 2 was released in April 2000, and the fan base started to grow rapidly. The breakthrough release came one year later, when the constantly evolving and always improving OOTP 3 received outstanding reviews and became the game to beat in the baseball simulation world.

Not satisfied, the OOTP team continued to strive towards making improvements. With the help of a growing and active user community, OOTP Developments released OOTP 4, 5, and 6 over the next several years, garnering numerous industry awards in the process. Infogrames published OOTP 4 under the name Season Ticket Baseball in the years 2001 and 2002, but the product became an industry casualty when other sports products in Infogrames' line fell short of expectations.

By late 2004, OOTP was up to version 6.5, and Markus had found that there just wasn't much more room for growth in the existing code base. In 2005, OOTP announced a partnership with Sports Interactive, a U.K.-based company well-known in Europe for its Football Manager simulation that had built a rabid following among European soccer fans. As part of this partnership, Markus rewrote the entire game from the ground up, taking advantage of new coding technology and SI's development platform.

The result was OOTP Baseball 2006, released in May of 2006. OOTPB 2006 was an extremely ambitious leap forward for OOTP. Whereas previous versions of the game had allowed some degree of customization, the league structure had always been fixed. That is, every OOTP game consisted of one league with no more than 3 levels of minor leagues. OOTPB 2006 blasted away those barriers, opening the way for users to create baseball universes with as many leagues as they wished. But after a long and difficult development cycle, OOTPB 2006 suffered from some growing pains, struggling a bit with its own scope and complexity.

The following year, however, the development team had an opportunity to revise and refine the interface and the feature set. Historical simulations received some great new features, as did online league commissioners. OOTP Developments also added FaceGen technology to create realistic faces for fictional players. The result was OOTP Baseball 2007, which dramatically reversed the disappointment of 2006 and received critical acclaim throughout the sports gaming community.

In September of 2007, OOTP Developments announced an amicable split with Sports Interactive, who had since been purchased by SEGA. In the wake of this split, OOTP Developments released their own branded version of OOTPB 2007 called "OOTP 8," which is now the current release of the game.