"Hubert Selby Jr - It Will Be Better Tomorrow" is an intimate and engaging documentary that focuses on the life and work of the celebrated American author, Hubert Selby Jr. As a profound and influential writer, his work has carved a significant niche in global literature, making this documentary a treasure mine for book enthusiasts and critics alike. Nevertheless, it also speaks volumes to those with a taste for compelling life stories that are layered with complexities, survival, and resilience.

Directed by Michael W. Dean and Ryan Sarno, "Hubert Selby Jr - It Will Be Better Tomorrow" unravels the enigmatic persona of Selby, often known as 'Cubby' among his friends. The film ventures into the profound depths and intricate detailing, following the threads of his life that are intertwined with his work. It showcases his journey from a merchant mariner to combating tuberculosis, from battling drug addiction to ultimately turning towards creative writing, this cinematic piece covers it all.

The documentary carefully balances elements of Selby's personal anecdotes, professional milestones, and highlights of his masterpieces. It brings together his experiences and struggles that are strongly echoed in his stark and gripping narratives. A central theme of the film is Selby's resilience in the face of life-threatening illnesses and addictive behaviors, a story as captivating and intense as his writing.

The greatness of the film lies in the excellent narrative structure that seamlessly merges interviews, archival footage, and readings from Selby's works. The archive footage gives an almost pristine glimpse into Selby's life, while the readings from his works add an additional emotional undercurrent to the movie. The testimonials from celebrities, family members, and friends further provide a more comprehensive view of Selby as a person and as an author.

Casting a distinguished list of commenters, including Ellen Burstyn, Lou Reed, Henry Rollins, Jared Leto, and Uli Edel, the documentary explores the significant influence that the author's works have had on a wide range of artists and performers. Galvanized particularly by Selby's gritty realism and empathetic depiction of life at the margins, these acclaimed faces add an enriching layer to the film’s portrayal of Hubert Selby Jr's creativity. Jared Leto's heartfelt narration ties the entire film together, creating a thought-provoking sagacity that persists throughout the documentary.

Additionally, the film touches upon the importance and impact of Selby's seminal literary work, "Last Exit to Brooklyn". This controversial and celebrated piece, recognized for its explicit content and raw portrayal of human depravity, has gained a significant place in the history of American literature. It gives valuable insights into the backdrop of Selby's writing, as well as the critical and public reception of his work.

The pacing and cinematography of the documentary are meticulously crafted, making the viewing experience immersive and absorbing. The skill of the directors is evident in their ability to tackle such a complex life story with grace and sensitivity. Moreover, they skillfully encapsulate Selby’s spirit and literary significance in this well-executed piece of work.

"Hubert Selby Jr - It Will Be Better Tomorrow" serves not only as a captivating exploration of Selby's life and works, but it also sheds light on the inner workings of the literary world. It takes viewers on a journey that meticulously traces the trajectory of a man who rose from life’s adversities to produce literature that marked an era. It’s a compelling testament to the power of creativity, resilience, and the human spirit, one that stays with you long after the closing credits roll.

To conclude, the documentary "Hubert Selby Jr - It Will Be Better Tomorrow" provides a profound exploration of the life, struggles, and triumphs of an iconic American writer. It is a valuable watch for those who appreciate literature, complex life narratives, and tales of persistence. The film is indeed a fitting tribute to Hubert Selby Jr., capturing the essence of a man who dared to bare the realities of life through his compelling prose.