Kids ages 4 to 12 can run the bases after every Sunday day game. Dates this season are: April 7, 14 and 28; May 5; June 9 and 23; and Sept. 22. An adult must accompany runners to the field. Starting at first base, kids will be directed to run around the bases as the adults continue along the warning track and meet the runners near home plate. The line forms outside of the park on the sidewalk along First Street washington.nationals.mlb.com.