I got the opportunity to meet Larry McMurtry at his "city of books" in Archer City, Texas--the small West Texas town he based Anarene, the setting of this movie, on. I asked him why he had been pretty lucky with movies based on his books, compared to some authors. He didn't have much of an explanation, but agreed that some of the movies turned out well--Lonesome Dove, Terms of Endearment. The Last Picture Show turned out the best, in my opinion. The cast is uniformly excellent, but Peter Bogdavovich's direction is just right. And the choice to use black and white film was brilliant. A true classic book and movie.
For more on McMurtry's ups and downs in the movie biz, read his interesting book Film Flam.