Since 1996 (the first full season with at least one Wild Card), 69 of the 126 division champions (55 percent) held at least a share of that division lead entering May 1.
Historical trends
Does it feel like teams are better this year? They are. There are just three teams with a winning percentage below .400 entering May 1 this season, tied for the fewest such teams in any season since 1996 (also in 2009).
Since 1996, 14 of the 21 World Series winners led their divisions entering May 1. The 2014 Giants, 2011 Cardinals and 2004 Red Sox each had a share of their respective division’s lead at that point, did not win the division, but did win the World Series.