So here I am pushing 70, and I finally found something my teen-aged son actually wants to do with me--chase ball parks. We did our two local parks (SF Bay Area) when he was younger, then started doing trips. 2010 was San Diego-Anaheim-LA, then 2011 was SF to Chicago White Sox to Dallas to St. Louis to Philadelphia to Washington to Atlanta to Tampa Bay to Miami back to SF, 8 parks in 12 days. This year we're just now buying tickets, but it looks like SF to Denver to Milwaukee to Baltimore to…