Fans of Major League Baseball can already mark their calendars for March 12th and 13th. Those are the days for 2010's Big League Weekend at Cashman Field which again will feature the Chicago Cubs and their Windy City rival the Chicago White Sox. The announcement was made by the Las Vegas Convention and Visitors Authority and the Las Vegas 51s, the Triple-A affiliate of the Toronto Blue Jays. It'll be the second straight year that the two teams will meet at Cashman. The rivals set the all-time attendance record at Cashman in 1993 when they drew 15-thousand-25 fans.