At the moment, some of the Australian football teams have been accused of ‘tanking’ (see Phrase of the Week in ‘More’ to get meaning) because then they will get priority in picking their players next year.  Click this link to read a news article about tanking:
http://www.theage.com.au/news/rfnews/voss-wants-a-life-ban-from-afl-for-any-coach-found-tanking/2009/08/03/1249152558487.html

Do you know any other examples of ‘tanking’?

Is this the same as ‘throwing’ a game?  - trying to lose?

Yes, I reckon ‘throwing’ is the same as ‘tanking’