NEW YORK — CoCo Vandeweghe made it three Americans into the U.S. Open women’s semifinals, beating top-seeded Karolina Pliskova 7-6 (4), 6-3 on Wednesday. The 20th-seeded Vandeweghe matched her best result in a Grand Slam tournament, having also reached the semifinals of the Australian Open in January before falling to Venus Williams. Williams is also
