<human>: Nathan Charles Buckley (born 26 July 1972) is a former professional Australian rules football player, commentator and coach, best known for his time as captain of the Collingwood Football Club in the Australian Football League (AFL). He is currently the senior coach of the Collingwood Football Club. He is listed by journalist Mike Sheahan as one of the top 50 players of all time. Buckley won the inaugural Rising Star Award, in 1993, then went on to become one of the game's elite, captaining Collingwood between 1999 and 2007, winning the Norm Smith Medal for best player afield in the 2002 Grand Final despite playing in the losing team, only the third player in history to do so, the Brownlow Medal in 2003, winning Collingwood's Best and Fairest award, the Copeland Trophy, six times and named in the Collingwood Team of the Century.

During his first season Buckley's arrangement with the Bears became common knowledge. At the end of the contract he attracted strong interest from all Melbourne-based clubs, chiefly Collingwood, Geelong and North Melbourne. However, it was Collingwood that successfully arranged a trade deal acceptable to all parties. Unbeknown to other AFL clubs and to the AFL itself, Collingwood and Brisbane had already agreed to make the trade happen. Collingwood selected ten players on its list who were "untouchable", and the Bears could take any two players outside this list, as well as the Collingwood Magpies' first round draft pick, in exchange for Buckley. The move saw Buckley move to Collingwood in exchange for Craig Starcevich, Troy Lehmann and the Magpies' first-round draft pick (no. 12, future double-premiership player Chris Scott).  Buckley was adamant that the move was the right career direction, with the belief he had more chance of winning a premiership with Collingwood. Ironically, Brisbane would beat Collingwood in two consecutive AFL Grand Finals in 2002 and 2003. In his first season with Collingwood, the Magpies were eliminated by the West Coast Eagles by two points in Perth.  From here, Buckley would be a consistent performer for Collingwood. As well as winning a Brownlow Medal in 2003, he finished in the top three twice before the turn of the century. He was also named Collingwood's Best and Fairest six times in 10 years (including one tied), as well as six consecutive years in the All-Australian Team from 1996 to 2002.  In 1999, Buckley suffered a broken jaw playing against Carlton in Round 2. He returned in Round 8 to help Collingwood to their first win of the season and their first in 13 matches. Collingwood finished the season last, only the second time in their history (the other being in 1976). Buckley also competed in the last game at Collingwood's long-time home ground Victoria Park against one of their main rivals, the Brisbane Lions. CANNOTANSWER

What led him to stop playing for Collingwood?
<bot>: CANNOTANSWER