For all players of the game, Backgammon the book is surely the sine qua non, to borrow Renée Robert's dedication phrase.
I have a mint condition copy of the 2004 edition, given to me by Renée herself together with a signed note from her. The forward to this edition, written by Renée, is a fascinating and sometimes poignant résumé of her time with Paul Magriel, and of her continuing friendship with him since then.
As for the book itself and as Renée acknowledges in the forward, the bots have overtaken it to a very small extent in respect of the opening rolls and in the designation of the so-called golden point, and it skims over doubling somewhat, but the vast majority of its content is as relevant and incomparably instructive as it ever was, although there is an amusing minor typo in the Tables section where it gives the probability of hitting a blot 24 pips away as 3/36 (sic), and in the main "Splitting" sections it says "A key criteria (sic) for deciding when to make a major split ....", and "This is the criteria (sic) .....".
Keep your eyes on the situation regarding any re-issue of this seminal book because, in acknowledging "..... a couple of specific areas that he (Paul) feels are lacking.", Renée continues in her forward, "Hopefully, this and other updated information will be included in later editions of Backgammon .....".
That was nine years ago now and so, whilst I personally continue to nurture this hope, I wonder whether Paul will ever turn it into reality?