On June 28, 2007, he and Glen Davis were dealt by the Seattle SuperSonics to the Boston Celtics in exchange for Jeff Green, Wally Szczerbiak, Delonte West, and a 2008 second-round lottery selection (Trent Plaisted was later selected). Signed as a free agent with the Miami Heat on July 11, 2012. On November 1, 2016, he announced his retirement. He will be honored during a ceremony before a game between the Heat and Indiana Pacers. Allen joined the Sonics after playing one season with the Celtics, where he helped lead Boston to its first NBA title since 1986. The Sonics drafted him ninth overall in 1989. In 1990, he became just the third rookie in NBA history to score at least 20 points in each of his team's games played. The other two are Michael Jordan and Kevin Durant. He went on to play eleven seasons in Seattle and become one of the best three-point shooters of all time. In 2001-2002, he made 402 three-pointers, which is currently fifth all-time. The only players to make more three-pointers in a season are Ray Allen (441 in 2004-2005), Kyle Korver (440 in 2013-2014), and Stephen Curry (446 in 2014-2015). After leaving Seattle, Allen played one season with the Indiana Pacers before announcing his retirement. He finished his career with 2,928 points over 229 games (including playoffs). He is the son of Bill Allen and Anne Marie Kiley.