knight traping theory

One thing I saw: 3. d3. In King's Pawn openings, that's usually a mistake; it yields control of the center to black. Unless you're playing a hypermodern opening, it's usually better to go with d4.

10. Nh4 was a mistake. Better was to play Nb5, sticking a knight where it, if he was careless, might do the dreaded Nc7 fork.

 11.a3, 14.b3, again, it's usually better to move the B pawn 2 squares, or to move tha a and c pawns and keep the B pawn stationary.

15.f3, it's usually a bad idea to use the f pawn to do ANYTHING other than guard that diagonal when the h pawn is available- moving the f pawn can result in a pinned rook, a two bishop mate, a bishop/queen battery, or even an Arabian mate (rook+knight.)

16.Rb1 was a mistake, better was g4, continuing the assault on the bishop, or Ng6 (or a move that cleared the way for it), a Knight sacrifice that paves the way for an open H-line for a queen/rook, queen/bishop, or even knight/rook or knight/bishop mate later on, and would again have kept him on his toes, if you could puzzle out a good mate-threat line.

17.Nxd4, basic "guarded versus attacked" counting error.

20, a pointless rook shift. 21. Qe1, ditto, pointless queen shift; any attack along either diagonal would end fruitlessly. Probably better would've been some pawn-pushing, and seeing if you could build a rook-rook, rook-queen, or rook-rook-queen battery along the G file.

22. Better was Rb2, allowing a rook shift to the left to save the pawn and attack the bishop if he still tried to attack.

25. I would've gone for Qb1, forking Rook and Bishop and guarding the Rook.

Past 25: You see how he attacked the F diagonal to mate you? That's why you don't move the F pawn.

 Nota Bene: This is just a cursory examination; common mistakes I've read of, seen, and made.

I agree that 4.d3 wasn't optimal. It allowed SailingBiker1 to play 4 ... d4! immediately, attacking your bishop and dulling the attack on f7. Usually I don't like to make it too easy for Black to play it quickly ...

You played 1. e4, and your initial moves seem fine. Against a weak player, you could have tried maybe, 4. O-O, offering the e-pawn: the Morphy gambit. But your opponent isn't weak! So I can understand your reluctance to go into a sharp tactical line immediately. With someone rated that much higher than me I think I might avoid 1.e4 altogether and go with  1. d4 instead, hoping that way to get more quietly to a reasonable mid-game. I'll look at the rest later.

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