Residents are invited to watch the fourth annual Burlington Pride Softball Tournament beginning at 9 a.m. Saturday at the Center School field, 61 Center St.  Burlington Pride,  a Special Olympics softball team sponsored by the Recreation Department and the Rotary Club of Burlington, will host the tournament. The Burlington Pride team formerly took part in the Special Olympics softball tournament in Amherst each August. The local tournament has grown to include teams from other towns, with about 200 athletes taking part. This year there are teams from Brookline, Melrose, Natick, and Reading in addition to Burlington. Following the games, there will be a cookout and awards ceremony.