Radical Realignment was a plan for realignment set forth by then acting Commissioner Bud Selig in 1997. Selig's plan would have realigned baseball's leagues and divisions by geography. The plan was part of the Expansion of 1998 process. With the addition of two new teams, the Arizona Diamondbacks and Tampa Bay Devil Rays, Major League Baseball would now have thirty teams. As part of the expansion agreement signed with Diamondbacks owner Jerry Colangelo Arizona was guaranteed a spot in the National League. While American League owners wanted the added revenue of a new team in their own league as well, something that hadn't happened since the Blue Jays and Mariners joined the league in 1977. This would have caused both leagues to have 15 teams. This would have caused an Interleague series to take place every day, or teams to have certain weekends off.
The proposal called for baseball to be realigned into what amounted to an Eastern Conference, the AL, and Western Conference, the NL, similar to the NBA and NHL. The NL would feature two 8 team divisions, while the AL would be two 7 team divisions.
Another plan under consideration called for the Diamondbacks to move to the AL and the Royals to the NL, this was nixed by Colangelo. The players union also had concerns about having teams finish as low as 7th or 8th and instead offered proposals to have the AL keep its 5-5-4 structure while the NL became 4 divisions of 4 teams. Another problem with the plan was the fact that all owners had the right to refuse to change leagues. As discussions went on the Mets, Cubs, Reds, Pirates, Giants, Braves and Padres ownership groups all came out against realignment. Mariners designated hitter Edgar Martinez said that he would retire if the M's moved to the National League.
With a schedule deadline looming for the 1998 season the owners finally reached an agreement. Instead of having nearly half the teams in the league change leagues only one would change leagues and another would change divisions. The Diamondbacks were given their spot, as promised, in the NL West. The Devil Rays joined the AL East and the Tigers switched from the AL East to AL Central. The Royals were given the first option of moving to the NL Central, which they declined, which left it to Selig's own Brewers to move the NL. Even after that decision was made owners still continued to work on possible plans for future realignment, though none have come as close to happening as this one.