1.

[Now on to our next weapon, discoveries. We've already seen a couple discovered attacks in earlier positions in the course. This is a very powerful device, especially when the discovered attack is check, known as "discovered check", like in this position.

Here, white can win black's queen with the discovered checks, knight D4 or knight D2, both opening up the white queen's attack on the black king, while aiming the knight at the queen.

{B:64}{D:2000}{P:BKf8}{D:2000}{P:BPe6}{D:2000}{P:BQb3}{D:2000}{P:WNf3}{D:2000}{P:WQf1}{D:2000}{P:WKg1}{D:3000}{S:f3d4}{A:Cf1f8}{A:Cd4b3}{D:2000}{B:5k2/8/4p3/8/8/1q3N2/8/5QK1}{S:f3d2}{A:Cf1f8}{A:Cd2b3}{W:291a}{W:291b}

]

2.

[

{B:1r1r4/p1q3pk/Rn3pNp/3b3B/8/7P/P5P1/1R1K1Q2 b}{V:{SAVE}Here, you can really see the power of the discovery, because the black bishop can go after any white piece he wants to, because they are all on light squares. Now what's the best discovery?{W:292a}{W:292c};

$Bishop C4 discovered check, winning the queen.

  {S:d5c4}{D:1000}{A:Cc4f1}{A:Cd8d1}{W:292e}{W:sil1000}{J}

$d5c4;You got it! Bishop C4 discovered check, winning the queen.

  {A:Cc4f1}{A:Cd8d1}{W:yougotit}{W:292e}{W:sil1000}{J};

$c Incorrect. Remember, a discovery is a move which puts the king in check, when the moved piece doesn't attack the king directly.

  {W:theresbetter}{RETRY};

d5g2:$c Very good! Bishop takes G2 is one of the two best discoveries. There's one more. Can you find it?{A:Cg2f1}{A:Cd8d1}{W:verygood}{W:292d}{RETRY} ;

Look for a discovery that attacks two of the most valuable pieces..}

]

3.

[

{B:3r3k/p5pb/7p/8/1n4Q1/8/PP3P2/K6R b}{V:{SAVE}In this position, it's black to move, and win as much material as possible. You have to calculate several moves ahead here.{W:293a};

${S:b4c2}{W:sil500}{J}

$b4c2;Excellent work! {W:excellent}{J};

$c Incorrect. The goal of this exercise is to set up a deadly discovery.

  {W:notquiteit2}{RETRY};

Perhaps you can attack the king?}

]

4.

[Knight C2 check forces the king to B1. What's next?

{B:3r3k/p5pb/7p/8/6Q1/8/PPn2P2/K6R b}{A:Cc2a1}{D:1800}{R}{S:a1b1}{W:293b}{V:{SAVE}Knight C2 check forces the king to B1. What's next?;

$Knight E3 check, a powerful discovery. Next will be knight takes G4, winning the queen.

  {S:c2e3}{A:Ch7b1}{A:Ce3g4}{D:3000}{R}{S:b1c1}{D:1000}{S:e3g4}{W:294a}

  {W:sil1000}{J}

$c2e3;Good move! Knight E3 check, a powerful discovery. Next will be knight takes G4, winning the queen.

  {A:Ch7b1}{A:Ce3g4}{D:3000}{R}{S:b1c1}{D:1000}{S:e3g4}{W:goodmove}{W:294a}

  {W:sil1000}{J};

$c Incorrect. The goal of this exercise is to set up a deadly discovery.

  {W:notquiteit2}{RETRY};

c2b4:$cIncorrect. While this is a discovered attack, and you are moving the correct piece, you are not moving it to the best square.{W:notquiteit2}{RETRY};

c2d4:$cIncorrect. While this is a discovered attack, and you are moving the correct piece, you are not moving it to the best square.{W:notquiteit2}{RETRY};

c2a3:$cIncorrect. While this is a discovered attack, and you are moving the correct piece, you are not moving it to the best square.{W:notquiteit2}{RETRY};

c2e1:$cIncorrect. While this is a discovered attack, and you are moving the correct piece, you are not moving it to the best square.{W:notquiteit2}{RETRY};

c2a1:$cIncorrect. While this is a discovered attack, and you are moving the correct piece, you are not moving it to the best square.{W:notquiteit2}{RETRY}}

]

5.

[

{B:2r2rk1/pp1n2p1/2pqp2p/8/n3P2Q/1N4P1/PPP2PB1/2K2R1R}{V:{SAVE}Now it's white's move and win material. See the whole board. {W:294b};

$E5 attacks the black queen and opens up the fourth rank. So the white queen also threatens the black knight on A4. There is no way for the queen to move and defend her knight, so white will win a piece for a pawn. After queen takes E5, queen takes A4.A lot of the chess players have the habit of focusing on one part of the board. Here you can see the importance of seeing everything. {S:e4e5}{D:300}{A:Ce5d6}{D:2000}{H:h4}{D:100}{H:g4}{D:100}{H:f4}{D:100}{H:e4}{D:100}{H:d4}{D:100}{H:c4}{D:100}{H:b4}{D:100}{H:a4}{D:7000}{C}{R}{S:d6e5}{D:1000}{S:h4a4}{W:294c}{W:295}{W:sil1000}{J}

$e4e5;Good job! E5 attacks the black queen and opens up the fourth rank. So the white queen also threatens the black knight on A4. There is no way for the queen to move and defend her knight, so white will win a piece for a pawn. After queen takes E5, queen takes A4.A lot of the chess players have the habit of focusing on one part of the board. Here you can see the importance of seeing everything. {D:300}{A:Ce5d6}{D:2000}{H:h4}{D:100}{H:g4}{D:100}{H:f4}{D:100}{H:e4}{D:100}{H:d4}{D:100}{H:c4}{D:100}{H:b4}{D:100}{H:a4}{D:7000} {C}{R}{S:d6e5}{D:1000}{S:h4a4}{W:goodjob}{W:294c}{W:295}{W:sil1000}{J};

$c Incorrect. There is one move here that will set up an exchange of material that will end in white's favor. {W:notquiteright}{RETRY};

Look for pawn move}

]

6.

[

{B:r1bq1rk1/pppp1ppp/2n2n2/8/2BNP1N1/2P5/PP3PPP/R2Q1RK1 b}{V:{SAVE}Black to move and win material here. What do you think?Be careful here. Notice where there may be some potential for discovered attacks, and then be sure to prepare your tactic properly.{W:296a}{W:296b};

${S:f6g4}{J}

$f6g4;Excellent work! {W:excellent}{W:sil1000}{J};

$cIncorrect. There is one specific move here that will lead to black winning material.{W:notquiteright}{RETRY};

d7d5:$c It's the right idea, but there's better. Here, white has an in-between move, Nxf6+.

  {S:g4f6}{A:Cf6g8}{D:800}{R}{S:d8f6}{S:e4d5}

  {W:theresbetter}{RETRY};

Be careful here. Notice where there may be some potential for discovered attacks, and then be sure to prepare your tactic properly. Look for knight move.}

]

7.

[Knight takes G4. Queen takes G4. D5, opening up a discovery on the queen and attacking the bishop on C4. Now, if white moves the queen, black will take the bishop on C4. But what happens if white blocks with knight F5? Remember, no mechanical thinking. Here it would be a terrible mistake to take the bishop, because then queen takes G7 would be mate. Often in chess, when you're just inches from victory, the opponent has some last tricks up his sleeve.

{B:r1bq1rk1/pppp1ppp/2n5/8/2BNP1n1/2P5/PP3PPP/R2Q1RK1 b}{D:1200}{S:d1g4}{D:1000}{S:d7d5}{A:Cd5c4}{A:Cc8g4}{D:10000}{R}{S:d4f5}{D:5000}{G:BPd5}{S:d5c4}{D:1000}{G:WQg4}{S:g4g7}{D:500}{A:Gf5g7}{D:2000}{Y:0}{B:r1bq1rk1/pppp1ppp/2n5/8/2BNP1n1/2P5/PP3PPP/R2Q1RK1 b}{S:d1g4}{S:d7d5}{S:d4f5}{Y:1}{W:296c}{W:296d}{W:296e}{W:sil500}{V:{SAVE}What should black play here?{W:296f};

$An in-between move. Bishop takes F5, removing the attacker of the G7 square, and after queen takes E5, only then D takes C4 wins a piece. So be careful to set your tactics up properly.

  {S:c8f5}{R}{D:5000}{S:g4f5}{D:1000}{S:d5c4}{W:296g}{W:sil1000}{J}

$c8f5;Very good! An in-between move. Bishop takes F5, removing the attacker of the G7 square, and after queen takes E5, only then D takes C4 wins a piece. So be careful to set your tactics up properly.   {R}{D:5000}{S:g4f5}{D:1000}{S:d5c4}{W:verygood}{W:296g}{W:sil1000}{J};

$c Incorrect. This one is trick, so think hard before making your move.

  {W:notquiteright}{RETRY};

Think about removing the attacker.}

]

8.

[

{B:b5k1/6P1/1p4PP/8/3p2P1/6NP/PPBPr1R1/Q4NK1 b}{V:{SAVE}This problem is extra tricky. White is up a huge amount of material, and black doesn't have forced mate. Seems like a recipe for disaster, but black to play and win. Take your time here. My guess is that this will be your deepest chess calculation yet, but try to find a pattern. Don't worry if this problem stretches your brain a little. The idea is to keep white in the box and take as much material as possible without letting him out of the box.{W:297a2};

${S:e2g2}{J}

$e2g2;Good work! {W:goodwork}{W:sil1000}{J};

$c Incorrect. Black can win if you find the right moves.

  {W:notquiteright}{RETRY};

Can you see a way to place the white king in check and support your attacking piece with another?}

]

9.

[Rook takes G2 check. King H1. And now?

{B:b5k1/6P1/1p4PP/8/3p2P1/6NP/PPBP2r1/Q4NK1 b}{D:1500}{S:g1h1}{W:297b}{V:{SAVE}Rook takes G2 check. King H1. And now? ;

$Rook takes G3 check. Discovery. Now of course the idea for black here is to take as much as possible without allowing white to stop the checks. So rook takes D2 would have been a terrible mistake, because then white could block the check with knight E4 and win the game.

{S:g2g3}{D:2000}{A:Xa8h1}{D:6000}{B:b5k1/6P1/1p4PP/8/3p2P1/6NP/PPBP2r1/Q4NK1}{D:1500}{S:g2d2}{D:4000}{S:g3e4}{D:2000}{W:297c}{W:sil1000}{J}

$g2g3;Yep that's it! Rook takes G3 check. Discovery. Now of course the idea for black here is to take as much as possible without allowing white to stop the checks. So rook takes D2 would have been a terrible mistake, because then white could block the check with knight E4 and win the game.

{D:2000}{A:Xa8h1}{D:6000}{B:b5k1/6P1/1p4PP/8/3p2P1/6NP/PPBP2r1/Q4N1K}{D:1500}{S:g2d2}{D:4000}{S:g3e4}{D:2000}{W:yepthatsit}{W:297c}{W:sil1000}{J};

$c Incorrect. Don’t be discouraged if you struggle with this one. Think of the concepts you have learned in previous lessons.

  {W:notquiteit2}{RETRY};

Look for a discovery that captures a piece.}

]

10.

[After rook takes G3 check, you see you're actually checking and removing the defender of the E4 square. White has to move the king. King H2. Now if you haven't found the answer yet, then take your time and work from here.

{B:b5k1/6P1/1p4PP/8/3p2P1/6rP/PPBP4/Q4N1K b}{D:5500}{S:h1h2}{W:297d}{V:{SAVE}After rook takes G3 check, you see you're actually checking and removing the defender of the E4 square. White has to move the king. King H2. Now if you haven't found the answer yet, then take your time and work from here.;

$Rook G2 check. King H1. Rook takes G4. King H2. Of course, if the white bishop ever blocks with bishop E4, then bishop takes E4 check and it doesn't matter.

{S:g3g2}{D:2000}{S:h2h1}{D:1000}{S:g2g4}{D:1500}{A:Xa8h1}{D:1000}{R}{D:500}{S:h1h2}{D:1500}{G:WBc2}{S:c2e4}{D:2000}{G:BBa8}{S:a8e4}{D:2000}{W:297e1}{W:sil1000}{J}

$g3g2;Excelent work! Rook G2 check. King H1. Rook takes G4. King H2. Of course, if the white bishop ever blocks with bishop E4, then bishop takes E4 check and it doesn't matter.

{D:2000}{S:h2h1}{D:1000}{S:g2g4}{D:1500}{A:Xa8h1}{D:1000}{R}{D:500}{S:h1h2}{D:1500}{G:WBc2}{S:c2e4}{D:2000}{G:BBa8}{S:a8e4}{D:2000}{W:excellent}{W:297e1}{W:sil1000}{J};

$c Incorrect. Don’t be discouraged if you struggle with this one. Think of the concepts you have learned in previous lessons.

  {W:notquiteright}{RETRY};

Look for a move that places the king in check.}

]

11.

[So the king goes to H2, now the rook returns to G2 check, forcing the king back into the box. King H1. Now you can go on to capture all the pawns and pieces on the second rank. 

So now your tactical arsenal is complete. The last exercise you did was designed to reinforce how important it is to learn basic patterns and then apply them in complex situations. By recognizing a pattern of discovered checks, suddenly you were able to do a twenty move chess calculation. This type of learning, by building from the core out, is central to my approach to chess. Now let's move on to the Mastery Quiz, which should reinforce the ideas we've been discussing.

{B:b5k1/6P1/1p4PP/8/3p2r1/7P/PPBP3K/Q4N2 b}{D:1000}{S:g4g2}{D:1500}{S:h2h1}{W:297e2}{W:298}

]

