Kristian Bak Nielsen

Midtjylland

Born in Kibæk, Herning Municipality, Bak's first football club was Kibæk IF, but he already started began playing in the youth department of Ikast fS at age 16. Ikast fS later merged with Herning Fremad and created FC Midtjylland. Bak started his senior career with Midtjylland in 2000. He helped the club win the 1999–2000 Danish 1st Division and gain promotion to the Danish Superliga. In his first years at the club, he played as a striker, but eventually settled as a centre-back. He played all Midtjylland's matches during the 2003–04 Danish Superliga season and was rewarded with a new contract in November 2004, keeping him at the club until 2007. In 2005, he became the club's captain.

Heerenveen

On 19 June 2007, Bak signed a four-year contract with the Dutch Eredivisie club SC Heerenveen. He was sidelined with an ankle injury from the end of the December 2007. He made his league return on 5 October 2008 in a 5–2 win over Ajax. He played a total of 72 league matches for Heerenveen through three seasons. On 10 February 2010 he was fined €1,000 by the Royal Dutch Football Association (KNVB) prosecutor for allegations against referee Kevin Blom. Bak was also given a conditional suspension of one match. He had claimed after a 2–1 loss to ADO Den Haag that Blom had deliberately let the opponent win: "After the 1–1, I asked Blom what he was doing. He said he wanted ADO to win," he told on the Heerenveen website.

Return to Midtjylland

In…

Bak was first called up for the Danish under-21 national team in October 2003. He played a single under-21 national match, against the Bosnia and Herzegovina under-21s. He replaced Thomas Kahlenberg in the extra time of the second half, in a match which Denmark won 3–0. On 20 November 2006, he was called up for the Denmark League XI, playing unofficial games against the United States, El Salvador and Honduras in January 2007, by national team manager Morten Olsen. He was called up for the Danish national team in March 2007 as a replacement for the injured Per Nielsen.

After he retired from football in 2016, he was announced as the new assistant coach of the club. In May 2019, Bak joined Denmark Series 4 amateur club TIF All Stars. In June 2022, Bak changed position in Midtjylland to assistant Sporting Director.

Bak married Diana Bach on 16 November 2013, and on that occasion changed his name from Kristian Bak Nielsen to Kristian Bach Bak.