Peter Markle won praise for his debut feature "The Personals" (1982), a sincere study of a man re-entering the dating world after his wife leaves him, and had a surprise hit with the middling teen comedy "Hot Dog...The Movie" (1984). He used his own experiences as a member of the US National Hockey Team as the basis for "Youngblood" (1986), an earnest but pedestrian behind the scenes look at the sport that featured Rob Lowe and Keanu Reeves. Markle had perhaps his best shot with "BAT 21" (1988), a Vietnam War drama about an American officer (Gene Hackman) caught behind enemy lines and the