NEW YORK (AP) — Seven-inning doubleheaders and runners on second base to start extra innings will return as experiments for a second straight season under an agreement for 2021 health protocols reached Monday between Major League Baseball and the players’ association. The deal did not include last year’s experimental rule to extend the designated hitter to the National League or expanded playoffs. After allowing 16 teams in the postseason last year instead of 10, MLB has proposed 14 for this year before withdrawing that plan last month. Last year’s expanded playoffs agreement did not come together until hours before the season’s first pitch.