9 Bxc3 Qxa3

9 dc3 Qxe5

Material balance:

1)equal points

2)Black has traded the dark square bishop for a
knight

Positional considerations:

1)The positions of the two sides are
unbalanced(asymmetrical) which naturally
increases the likelihood that the best move will
be a tactical move as opposed to a positional
move.

2)Both kings are uncastled

3)Both sides have unusual development:

a)the queens for both players are out early

b)the Black queen is better placed than the
White queen. In fact the White queen has few escape squares so trapping it may be
possible.

c)both sides are lacking in development, but
both sides are threatening to trade pieces.
White has the threat of material gain on c4.

d)White has a centralized knight but because of
his lack of development he can't coordinate
this knight with other pieces to put real
pressure on any particular point.

e)White's fianchettoed bishop can attack the
undefended g7 square if the e5 knight moves.

f)Black's fianchettoed bishop hampers kingside
castling for White because of the pin of the g2 pawn and the pin of the f1 bishop which must
guard the g2 pawn. But because Black has
already traded of his dark square(long range) bishop, it will be hard for him to generate any direct mating threats. To further this point, one can note that even though the position is open, neither side has good development and
so can't bring their rooks into play yet.

g)Both players have the option of trading queens
which will decrease the likelihood of a mating
attack in an open position.

h)Black's queenside pawns are very advanced for this stage of the game. This could become a
liability if they can't be defended properly.

Strategy 1: Black plays a kingside pawn move

Analysis: too slow and also antipositional. The move f6 (as played in the game) may be good because it nullifies the effectiveness of the b2 bishop and forces the e5 knight to leave the center. Also note that due to the back pawn on b5 , it's difficult for white to exploit the opening of the a2-g8 diagonal. I would consider this move if nothing more forcing is found.

Strategy 2: Develop the g8 knight and get the Black king to safety by castling.

Analysis: If the Black knight comes to f6 and thence to e4 or g4 it can only pressure dark squares in White's position, but we already know the Black dark square bishop is gone so it will be naturally harder to put real pressure on these squares. Castling is good positionally for Black, but the Black king is in no real danger despite the open position because White can't coordinate forces to attack it. Thus this strategy seems too slow given the situation, not to mention the fact that White is threatening to win material on c4.

Strategy 3: develop the queenside knight.

Analysis: Moving the knight to d7 or c6 has a tactical refutation and also a positional refutation. The tactical refutation is the weakness of the g7 point. The positional refutation is the fact that such a move allows several exchanges which decrease Black's tactical chances, and thus increase the relative severity of Black's queenside pawn weaknesses. Moving the knight to a6 is too slow and allows White to win immediately after Qxd6 cxd6, Nxc4 bxc4 Bxg7 Nb4 Kd1 etc.

Strategy 4: Move the bishop on b7 or queen on d6 to create a tactical threat.

Analysis: The b7 bishop cannot be improved on any square, nor can it create any tactical threat since all of White's pieces are guarded. Same for the queen. Nothing in White's camp is unguarded(thus prone to forking) and Black can't coordinate other forces with the queen to increase pressure anywhere.

Strategy 5: Look for tactics involving queenside pawn advances.

Analysis: Intuitively, this seems the most correct due to the unusual position of the White queen and also the fact the the b2 bishop must guard both a3 and e5 and hence may be subject to 'overload' or 'deflection' tactics. You'd want to look at these moves first, and if they don't work out, look for some other positional move.

Calculation: So the candidates are ...b4 and ...c3.

If ...b4(attempting to trap the queen White can play Qa4+ Bc6(...c6 or ...Nc6 allow the simple Nxc4), Nxc4!(Nxc6 Nxc6, Bxg7 0-0-0, 0-0-0 wins for White as well but it is harder to calculate...it's easier just to eliminate the move ...b4 with a simple line) ...Bxa4, Nxd6+ cxd6, bxa4 and White relieves pressure by trading pieces and has an extra pawn.

<Once> Great Story!

<Patriot> Good work Today! This wasn't exactly straightforward: took getting some hands dirty, so to speak

See Ed. Lasker's 1942 book, _Chess for Fun and Chess for Blood_. My copy is the 1962 corrected reprint by Dover Publications. Chapter 10, "Tournament Ethics", is written around a detailed analysis of this game, including the part where Lasker points out that he overlooked 8...c3 (pp. 197-198).

This game went on to form a standard book opening trap, being the 300th and final entry in Irving Chernev's _Winning Chess Traps_ (1946).

9 dc3 Qxe5 -- same