New moves in opening

A lot of times we run into moves immediately out of the opening that we never thought were possible. It's difficult to know what to do when we see uncommon opening moves like

1. e4 c6 (CaroKahn)

2. e5!?

or

1. e4 e5

2. c4!?

or

1. e4 d5

2. e5!?

One thing to always keep in mind is that these are not theoretical book moves for a reason. The benefit of this knowledge is that you immediately know you have an advantage and the solution is somewhere out there - you just have to find it.

Here is a game I played where as black where I ran into a move I'd never seen before right out of the opening. Time controls are 15 min each side, no increment.

This was an easy problem because you have all the answers right in front of you. You don't need to know the best move or be able to "find it from scratch" All you need to know is 

1) Qd4 is unusual and I know it's not book.

2) My knight is attacked and it must be defended or moved. Since it can't move anywhere nice...d6 or h5 must be the answer. Since h5 doesn't do anything except bow to his bologna Qd4....d6 must be the answer! 

What does d6 do: It defends the knight, opens development for the bishop, and attacks the white pawn. Black needs compensation for his pawn and must do so in the form of development. Sacrificing another pawn or two is absolutely called for.

Note that d5 also accomplishes these things - except for attacking white's center. d6 makes this possible. Also - Bb4+ is a possiblity but it does nothing to capitalize on black's development. It will result in a trade of pieces - pieces which you want ON the board (the more pieces off the board means the more powerful white's extra pawn becomes). 

So therefore, of the cadindate moves (d6, h5, d5 and Bb4+): d6 is the best and it is the only move which demands the advantage for black. It gives up material for activity and development.

Here is the rest of the game.

This is good practical opening advice and once you learn openings to even more depth (not just to move 2), you'll be able to deduce what the best move is. Here is an example of what to do in the scotch game when an unusal move is played a little further down the line.

So in this last example, if you know some opening theory you know that the moves are 7. Bc4 Ne5 8. Be2. If a white player immediately plays something like 7. Be2 you know it is NOT book opening. You know that Bc4 IS book opening. So ask yourself "Why is Bc4 correct but not the immediate Be2? What does Bc4 do?" It either attacks f7 or protects d5 or just develops a peice to make way of castle. But Be2 makes way and develops as well....so why is Bc4 correct? These are the questions you have to ask yourself to find the best move. Once you realize that Bc4 prevents the immediate d5, yet your opponent played the inaccurate Be2, then if you're playing black you should instantly start to analyze d5! After d5, black has equalized. Yes - it is not a tyrant of a move or a game changer - but it seizes the center and removes white's initiative. 

Another great example is the Evan's Gambit after 1. e4 e5 2. nf3 nc6 3. bc4 bc5 4. b4 Black's only book move is to accept the sacrifice. However sometimes you will see the bishop retreat with Bb6 or the knight take the pawn with Nxb4. What does white do here?

Use the method. Ask yourself "Why isn't this a book move. What does it enable white to do which demands the advantage. If there wasn't a move which demanded the advantage, then black's move would be a correct book move! Since it is not, there must be a way to exploit it." 

However, the Bb6 move is more difficult and has actually been used in many games. See the last game in http://blog.chess.com/MacMolner/the-best-chess-player-youve-never-heard-of

What are white's options for his next move? Why is black forced to take on b4? By retreating the bishop there must be something to exploit. So what are the candidate moves? First off, the b4 pawn is alive and well (as opposed to being gone in all main line theoretical variations) so b5 is absolutely worth a look. Also black has "wasted" a tempo by moving his bishop twice so making more development with Nc6 and 0-0 is an option. And now white has a lot of nice space that wouldn't of been there due to the bishop retreat so moves like a4, gaining more and harassing the bishop, are options. 

So our options are b5, a4, 0-0 and Nc6. Now that you have candidate moves, those are the only ones you have to evaluate. Now let's take it to the next step. We are white so naturally since we chose this opening we are familiar with it. So now practical chess comes into play. Do you want to delve into something like b5 which leads to wild complications your not prepared to play? (However, black MIGHT be prepared since he played Bb6!? instead of the book move bxb4). Take a look:

SO although b5 answers all the questions of "how can we exploit black's novelty" and MAY lead to an advantage - you will be on your own in wild complications. Fischer was famous for entering these complications, sometimes without seeing the light at the end of the tunnel.

Nc3 is a similar beast - it is a good move but will take you out of the normal Evan's Gambit ideas, making you think for yourself. You want to use your memory as an advantage! So moves like a4 and 0-0 are great!

So psychologically, it may be better to 0-0 or play a4 to avoid complications. Fischer said "I don't believe in psychology, I believe in good moves." There is a good chance that Fischer would play b5! knowing that his tactical acumen and chess genius would be enough for a win. But playing something like a4 isn't just psychology - it is practical chess. Play what's comfortable!

Chess isn't just finding the best move like a machine would through tactics and 1,000 variations and possibilities. Some deduction is definitely called for. Use everything you know! Not just your ability to solve puzzles. 

in the last one: i would ve just tried

1.b5 Nd4 2.Bxf7+ Kxf7 3.Nxe5+ Ke8 4.Qh6+

and see how it goes from there :)