John Maine's journey through Major League Baseball is a tale of perseverance and skill on the pitcher's mound. Born on May 8, 1981, in Fredericksburg, Virginia, Maine attended the University of North Carolina at Charlotte, where he honed his pitching abilities. His talent caught the attention of scouts, and in 2002, he was drafted by the Baltimore Orioles in the sixth round of the MLB Draft.

Maine made his MLB debut with the Orioles on July 23, 2004. During his time with Baltimore, he showed potential but struggled to find consistency. Over the course of two seasons, he appeared in 11 games, starting 9 of them, and posted a 6.60 ERA. Despite these challenges, his potential was evident, and he became part of a significant trade.

In January 2006, Maine was traded to the New York Mets as part of a deal that sent Kris Benson to the Orioles. This move proved to be a turning point in his career. With the Mets, Maine found more opportunities to showcase his abilities. During the 2006 season, he became an integral part of the Mets' starting rotation, especially during their playoff run. Maine's performance in the postseason was commendable; he started Game 6 of the National League Championship Series against the St. Louis Cardinals and delivered a crucial win, helping the Mets force a Game 7.

The 2007 season was arguably the highlight of Maine's career. He started 32 games for the Mets, achieving a 15-10 record with a 3.91 ERA and 180 strikeouts. One of his standout performances came on September 29, 2007, when he pitched 7 2/3 no-hit innings against the Florida Marlins, ultimately allowing just one hit and striking out 14 batters. This performance kept the Mets in contention for the playoffs until the final day of the season.

Injuries, however, began to take a toll on Maine's career. The 2008 season saw him struggle with shoulder issues, limiting his effectiveness and leading to surgery to remove a bone spur. Despite these setbacks, he managed to post a 10-8 record with a 4.18 ERA in 25 starts. The following seasons were marred by further injuries, and Maine's time with the Mets came to an end after the 2010 season.

After leaving the Mets, Maine attempted to revive his career with the Colorado Rockies, signing a minor league deal in 2011. However, he was unable to make a significant impact and was released before the season began. He continued to pursue opportunities, signing with the Boston Red Sox and later the New York Yankees, but did not make it back to the major leagues with either team.

In 2012, Maine signed with the Miami Marlins, where he made a brief return to the majors in 2013. He appeared in four games as a relief pitcher, but struggled with control, posting a 12.27 ERA before being designated for assignment. This marked the end of his time in Major League Baseball.