 Complete the following phrase:  Starting with the 2021 season with the introduction of the 17-game season, Fox and CBS each have eight doubleheader weeks during the season between weeks 2 and 17 with both networks having the doubleheader for weeks 1 and 18. These are not necessarily alternating weeks; one network may have two or rarely three consecutive doubleheaders; this only occurs when one network has a doubleheader weeks 2 and 3 after both networks had the doubleheader in week 1, or in weeks 16 and 17, and then both networks have doubleheaders week 18; has happened to Fox 2019 and CBS in 2018. Fox requests to carry a doubleheader on the Sunday it airs a World Series game typically Game 5, and uses the featured 4:25 game as a lead in for the baseball playoffs though in 1996, 2001, 2005, 2014, 