Cannot praise these free vids enough.
Here is another good one told by Martin in his relaxed
grab a pint, pull up chair and look at this style.
After 1. e4 Nf6 2. e5
Black plays 2...Ng8 which I have seen referred to as the Boomerang
or the plain 'Knights Retreat' or The Petrosian Variation.
Is the pawn on e5 weak or strong?
Andrew gives some games of own to show the debate is open.