The first diagram illustrates "why" it was a bad move it was to place the queen on f6. Like you said, it violates opening principles, bringing the queen out early, leaves c7 vulnerable, but also shows how the knight cannot get to its most active square (f6), and now the dark square bishop is blocked. Leaving nothing but the king to defend c7.
Nice illustration of how whites violation of opening principles of moving the knight twice is OK in this position.
Here’s a pretty though slightly-flawed 3-day/move game I just won that illustrates some key guidelines for playing good chess.
I just wrote this as one of a series of pieces I send to a relative who coaches a middle school chess club. I hope the principles examined will benefit some players here and demonstrate the value of Fred Wilson's book, Simple Attacking Plans - I don't personally know Fred, but I love the book!
I had the White pieces in the game below which is posted interactively near the bottom of this post and can be viewed interactively at: https://www.chess.com/daily/game/201911236
The main things this game shows are:
P.S. Note: In some of the comments below it's mistaken or assumed Fred Wilson is a low or club-rated player (since Fred Wilson is a common name, maybe there are others). Wilson is, in fact, a very good play and writer:
Fred Wilson, age 72, is rated 2210 (master level) by the US Chess Federation and has the 26th highest USCF rating of those 65 and over (Seniors): http://www.uschess.org/component/option,com_top_players/Itemid,371?op=list&month=1806&f=usa&l=R:Top%20Seniors.&h=Top%20Age%2065%20and%20Over
in 2003, Fred Wilson was named Chess Journalist of the Year by the Chess Journalists of America.
The opening moves reach a position called “The Italian Game” which the Italians call “Giuoco Piano” and which means “Quiet Game” but that’s misleading because it can quickly develop into wild attacks. Note that, in keeping with Fred Wilson’s 1stprinciple (at bottom): In the opening, whenever justified, relentlessly attack the weak squares f7 or f2, my c4-Bishop is pointing at Black’s f7 square and my f3 Knight is one move from doing the same. Black played his pawn to h6 to keep the Knight from doing it and starting a wild opening called “The Fried Liver Attack.”
I did not intend to play the Fried Liver Attack, but it is feared by so many Black players that the …h6 move of the the “Anti-Fried Liver Defense” may give an advantage to “standard” Italian Game players by causing Black to waste a tempo on a Pawn instead of developing a Piece.
The first key position is after my 6th move:
My moving the Knight is NOT a winning move for the Knight alone, though Stockfish 9 (set to 20 ply depth, analyzed post-game on the great freeware Lucas Chess), says it’s the best move and puts me ahead by over a Pawn Equivalent - probably because Black’s violation of another principle - Don’t move your Queen out too early - left his c7-Pawn vulnerable and forces Black to play:
And now his King cannot castle! I have him - at least temporarily - stuck in the middle! The Black King is now on the d-file instead of the e-file so my FIRST thought is to follow Fred Wilson’s principle #3 (at bottom), If your opponent’s king is trapped in the center, make every reasonable effort to open and dominate the e-file, and sometimes the d-file also, and dominate the d-file. I want to castle and move my c1-Bishop so I can get my rooks toward the center files (columns).
Above, I blundered and overlooked a great move, Bb6+ then Bxa5, but Stockfish 9 says I’m still +1.71 Pawn Equivalents ahead. As the game goes on, Stockfish finds a few “mistakes” I make where its preferred moves are “better” but more complicated, which means human players have greater chances of going wrong: and all my moves from here keep me with a winning advantage according to Stockfish 9.
Above, on my 10th move Qd2, I’ve achieved mobility for my Rooks as planned and did NOT let myself be distracted by Black threatening to trade my well-placed c4-Bishop for his Knight: besides, when he does so it will open-up the d-file for me when I retake the Knight with my d-Pawn.
One more thing is noteworthy: when I moved my Queen, I kept her aimed at the Black King. That not only follows another one of Wilson’s principles, #4 at bottom: If possible, point all your pieces at your opponent’s king, it follows advice from the best book on tactics I know, Martin Weteschnik’s Chess Tactics From Scratch, 2nd Ed., which which notes that lining up your Q, R, or B with your opponent’s King can result in great tactical opportunities.
Finally (above), on my 16th move, I’m able to put serious pressure on the d-file, attacking Black’s d6-Pawn which is pinned to the d-file by my Queen.
Black (above) tries to avoid serious problems by pushing his d-Pawn forward, but it doesn’t work.
Black (above) instinctively moves his Bishop to d7 to block the discovered attack and check by my Queen after dxc6. This let’s me get my Knight into the attack:
Black (above) moves his Rook and hopes I will trade my Knight for it, gaining an advantage for me. But there’s an old rule of thumb about Knights: A Knight on the 3rd rank is poised for attack. A Knight on the 4th rank is as good as a Bishop. A knight on the 5th rank is better than a Bishop. A Knight on the 6th rank is devastating!
I have a Knight on the 6th rank, so I looked for other moves that would let me keep the devastating Knight:
My 19th move, dxc6!! above is the winning move and Stockfish 9 says I’m 11.77 Pawn Equivalents ahead. The d7-Bishop is pinned and Black can’t take my c6-Pawn because I’d checkmate Black by taking the d7-B with my Queen.
Below, a couple moves later after taking Black’s d7-Bishop, I take the opportunity to grab another pawn: Black can’t take my Knight because of b8=Q check!
After each side grabs a Pawn, Black makes a bad move (below) that violates another principle: When you are behind in material: trade Pawns, not Pieces.
He also strips away protection from his King.
But there’s a method to Black’s madness. Black knows he’s far behind in material now. He knows he needs to try to attack me NOW. By exchanging Bishops, he opens up the h-file for his Rook and Queen to attack h2 - which would be checkmate and would follow Fred Wilson’s Principle (#2 at bottom): Most successful kingside attacks are directed against the squares h7 or h2, and they are often preceded by eliminating or driving off its defender.
Below: I saw that I could open up the e-file (again, Wilson’s Principle #3 at bottom) for my Rook (Principle #4 at bottom) by moving my Knight to g4 and that Black’s wide-open King would get mated if Black’s Queen took the Knight or Black tried to drive the Knight off with f5 - the eliminating or driving off its [h2’s] defender part of Wilson’s Principle #2, which Black knowingly or instinctively followed:
Below, after 25 Rfe1+, Black could have stretched out the game by playing …Re7, But the result would not be in doubt.
But after 25…Kf8? (above), it’s easy to visualize a mating net where White’s Q and N force the Black K to a mating position. I have a forced mate in 3 after 26 Qd8+ Kf7 (forced) 27 Ne5+ Ke6 (forced) then 28 Qe6 checkmate:
The interactive game (with chess.com max analysis):
Fred Wilson
Fred Wilson’s 4 principles from his excellent book Simple Attacking Plans where the 4 principles are demonstrated by 36 annotated games:
I have come to believe there are only four essential, even primitive, concepts which you must learn and understand in order to play successful, attacking chess - Fred Wilson