Around 6 p.m. Thursday, the Grand Central, Van Wyck, and L.I.E. will have traffic going to see the Mets and the Cubs, a Wild Card rival, or to the U.S. Open next door. Earlier in the week, The Amazins’ play the Braves 1 p.m. Sunday, and the Cubs 7 p.m. Tuesday and Wednesday. The Open starts Monday and has matches 11 a.m. and 7 p.m. Monday through Saturday. The 7 train or the L.I.R.R. to Mets-Willets Point are the only smart ways to go to Citi Field or Arthur Ashe Stadium.