Not only the PP variation of the Najdorf , but all variations with same structure
The hazard makes that I am confronted in my current CC games with not less than 4 games with a PP variation :
One is the classical PP variation of Najdorf
Another is in a Petroff (I am White ) and BlacK Played Qxb2 : I recover the pawn with benefit
Myself play Qxb2 against a Trompowsky
And last I am Black in a Scotch , and my opponent plays Qxg7
Is there a book that study this structure as a whole , and define when the pawn sac is sound , and when it is not?
Maybe something in the same spirit as "Sacrifices in the Sicilian" , by David Levy