Lessons completed: Every Pawn Structure Explained by GM Johan Hellsten

I recently completed the lessons series "Every Pawn Structure Explained" by GM Johan Hellsten at Chess.com, motivated by the "Back to Basics" approach. The format consisted of 30 pawn structures explained with video lectures (816 minutes total), along with 5 "challenges" for each, in which you choose a prompted best move in the position presented. This is truly an excellent resource for learning different structural fundamentals important to all game phases (opening, middlegame, endgame) and becoming exposed to typical plans for each side. All of the content was useful for building fundamental chess understanding, and I intend to periodically revisit the key ones most relevant to my games. For a full content list, see the top link above. 

Overall comments on the lessons:

• The initial video presentation of the pawn structures and key individual piece placement - without the full set of pieces on the board - was an effective method for introducing the core structural characteristics for both sides.
• Similarly, the highlighting by GM Hellsten of "dream positions" for both sides, including typical pawn/piece formations and breaks, as well as guidelines for piece maneuvers and exchanges, was very helpful for understanding middlegame planning and strategy.
• It might have been a bit more thematic to group together all the similar opening structures in the default order of the lessons' presentation, for example to have the Sicilian-related ones be sequential. However, one can do that manually by selecting "a la carte" from the full lessons list, as they don't have to be completed in the designated order.
• I found the "challenges" - basically "find the best move" quizzes typical - to have varying utility and comprehensibility. The initial prompts for the type of move to find in the position were sometimes a bit obtuse or misleading for me. For example "How do you win material?" was sometimes problematic, especially when the answer turned out to be an obvious capture with no additional material beyond that actually gained. The selection of GM-level games also meant that some of the tactical ideas were rather complex to visualize and discover - otherwise, of course, the losing GM opponent would have been able to see and avoid them in the first place.

Comments on the most personally relevant topics:

• The Isolated Queen Pawn (IQP) presentation kicks off the series, with a very lucid and thorough explanation of general principles, plans involving specific squares and pieces, and thematic tactical tricks involving the IQP. The explanation and illustrations of this common and imbalanced structure were the best that I have seen. In my games, I can reach it via either White or Black based on my openings, so it was also very relevant.
• The second video on hanging pawns was similarly enlightening for both using and combating them, again very relevant for the positions I can reach in the middlegame.
• Next came the Carlsbad structure, which despite playing multiple openings where it can result (as both White and Black), I had never really studied it in-depth before. Explanations of the typical plans are clear, although I'd have liked to have seen the typical queenside minority attack better illustrated with examples. As compensation, there is a brilliant illustrative sacrificial attacking game for White in the kingside attack scenario.
• Later on, the Hedgehog - which seems to be less popular nowadays - received an interesting treatment for both sides, although the typical White side setup normally reached via the English Opening with a fianchettoed light-square bishop was not presented.
• The Advanced French and Scandinavian structures were also very useful to see, since I will often get them via the Caro-Kann.
• GM Hellsten did a particularly good job of clearly explaining the central features of the Stonewall structure, probably the one I have the most practical and theoretical familiarity with. It was helpful to reinforce my understanding of those, plus draw attention to some attacking ideas like the f-pawn push.