sentences:  The tournament structure for each division's World Series is similar to that used for the Little League Baseball World Series.The tournament started in 1981, and was originally created for 13-year-old players competing in Little League's Senior League division (which at the time included 13- to 15-year-olds).In 1999, Little league spun a separate Junior League division off from the Senior League division, which included 13- and 14-year-old players (currently, 15-year-olds are also eligible if their date of birth is after May 1 of the current season).