Chartball [chartball.com] aims to make sports databases understandable and digestible through the use of sophisticated forms of data visualization. The website currently offers 2 different visualization applications.
"Interactive Hitting" focuses on exploring baseball statistics, by mapping the relationship between home runs (vertical axis) and strikeouts (horizontal axis) per player of a specific team. The size of each bubble corresponds to the amount of at bats for that player. The yellow bubbles represent the top power hitters, whereas the user can freely select pairs of teams to visualize, and adjust the range of the axes.
The interactive "Football" charts reveal the sequence of events during the past (American) football matches from 2007 to 2010, including how runs, passes and kicks follow up on each other, and how a team's position on the field progresses depending on who drives.
If that is not sufficient, there are some posters available as well.