2015-04-16

Fwd: Test I took

Here is our feedback on your performance:

You correctly judged whether White could force a win for 41 of the 48 positions.

1)

 

Your response was: Yes, White can force a win. 

This response was: Correct

White wins because he can use the opposition to convert his pawn after 1.Kf6 Ke8 2.Kg7 Ke7 3.f6+ Ke6 4.f7

2)

 

Your response was: Yes, White can force a win. 

This response was: Correct

White wins because he has the opposition after 1.Kd6 Kf8 [ 1...Ke8 2.Kxe6 Kd8 3.Kf7 Kd7 4.e6+ Kd8 5.e7+ Kd7 6.e8Q+ ] 2.Kxe6 Ke8 3.Kf6 Kf8 4.e6 Ke8 5.e7 Kd7 6.Kf7 Kd6 7.e8Q

3)

 

Your response was: Yes, White can force a win. 

This response was: Correct

White wins by converting his a4 pawn because Black has to lose time to capture the g3 pawn: 1.Kf4 Kf6 2.Ke4 Ke6 3.Kd4 Kf5 4.Kc5 Kg4 5.Kb5 Kxg3 6.Kxa5 Kf4 7.Kb6 Ke5 8.a5 Kd6 9.a6 Kd7 10.a7 Kc8 11.a8Q

4)



Your response was: Yes, White can force a win.

This response was: Correct

White wins because the Black king has to abandon his kingside pawns to capture White's outside passed pawn: 1.a4 d4+ 2.Kd3 Kb4 3.Kxd4 Kxa4 4.Kd5 Kb4 5.Kd6 Kc4 6.Ke7

5)



Your response was: Yes, White can force a win.

This response was: Correct

White wins because one of his pawns can break through after 1.f5!! Kd4 [ 1...exf5 2.h5 gxh5 3.g6 fxg6 4.e6; 1...gxf5 2.h5 Kd4 3.h6 ] 2.h5 Kxe5 3.f6 gxf6 4.h6+- fxg5 5.h7

6)



Your response was: Yes, White can force a win.

This response was: Correct

White wins by fixing all black pawns on the kingside first, and then creating an outside passed pawn: 1.g5! Kd6 2.a4 Kc6 3.b5+ axb5+ 4.axb5+ and White can win the black pawns on the kingside.

7)



Your response was: Yes, White can force a win.

This response was: Correct

White wins because his superior pawn structure allows him to create a passed pawn on the kingside: 1.Ke2 Ke7 2.Ke3 Ke6 3.f4 f6 4.Kd4 g6 5.g4 h6 6.h4 Kd6 7.e5+ fxe5+ 8.fxe5+ Ke6 9.b4

8)



Your response was: No, White cannot win by force.

This response was: Incorrect

White wins by attacking the weak h7 pawn to obtain a superior position for his king: 1.Kf3 Kd7 2.Kg4 Ke7 3.Kh5 Kf8 4.Kh6 Kg8 5.b4 Kh8 6.g4 Kg8 7.h4 Kh8 8.f4 Kg8 9.g5 fxg5 10.fxg5 Kh8 11.h5 Kg8 12.g6

9)



Your response was: Yes, White can force a win.

This response was: Correct

White wins because the Black pawns on the kingside are blocked, and White can create an outside passed pawn on the queenside by playing 1.c5+ bxc5+ 2.Kc4 and Black is in Zugzwang.

10)



Your response was: Yes, White can force a win.

This response was: Correct

White wins according to endgame tablebases because two white knights can mate against a single black pawn if this pawn is not too far advanced: 1.Kg5 Kh7 2.Ndf5 Kg8 3.Kf6 Kf8 4.Ng7 Kg8 5.Ne6 Kh7 6.Kg5 Kh8 7.Kg6 Kg8 8.Ng4 e3 9.Nf6+ Kh8 10.Ng5 e2 11.Nf7#

11)



Your response was: Yes, White can force a win.

This response was: Correct

White wins because his two knights can mate the black king before the black pawn queens: 1.Ng4 h2 2.Nh6+ Kh8 3.Nf6 h1Q 4.Nf7#

12)



Your response was: No, White cannot win by force.

This response was: Incorrect

White wins with his strong knight against the weak bishop because the black squares are also weak and allow the white king to intrude after 1.g5 fxg5 [ 1...f5 2.Kf3 Kd8 3.Ke3] 2.fxg5 Bc8 3.Kf4 a5 4.Ke5 Ba6 5.Kf6

13)



Your response was: Yes, White can force a win.

This response was: Correct

White wins because his bishop controls the square h8, where White can therefore queen his h-pawn: 1.Kg4 Kh7 2.Kf5 Kg7 3.h4 Kh7 4.h5 Kg7 5.h6+ Kf7 6.Bc5 Kg8 7.Kg6 Kh8 8.Ba3 Kg8 9.h7+ Kh8 10.Bb2#

14)



Your response was: Yes, White can force a win.

This response was: Correct

White wins by preventing the black king from controlling the square h8, where White intends to queen his h-pawn: 1.Bh7! Kf6 2.Kf4 Kf7 3.Kf5 Kf8 4.Kf6 Ke8 5.Bf5 Kf8 6.h7 Ke8 7.h8Q#

15)



Your response was: No, White cannot win by force.

This response was: Incorrect

White wins by exploiting the weakness of the black pawns which are on white squares and can therefore be attacked by the white-colored bishop: 1.Kc4 Be8 2.Kb4 Bd7 3.Bf3 Be8 4.h4 Bb5 5.g4 hxg4 6.Bxg4 Bd7 7.h5 gxh5 8.Bxh5 Be8 9.f5 Bd7 10.Bxf7 1-0

16)



Your response was: Yes, White can force a win.

This response was: Correct

White wins because he can create two connected passed pawns on the 6th rank that cannot be stopped by the black rook: 1.e6 Kc4 2.d7 Rb8 3.e7 Kd5 4.d8Q+ 1:0

17)



Your response was: Yes, White can force a win.

This response was: Correct

White wins by advancing his passed pawn and building the so-called Lucena bridge (shielding his king and queening pawn by using his Rook): 1.Kc6 Re2 2.d5 Kf8 3.d6 Kf7 4.Rc1 Ke8 5.Kc7 Rd2 6.Rc5 Rd1 7.Re5+ Kf7 8.d7 Rc1+ 9.Kd6 Rd1+ 10.Rd5

18)



Your response was: Yes, White can force a win.

This response was: Correct

White wins the black rook by playing 1.Rh8 (threatening to queen) Rxa7 2.Rh7+ Kg6 3.Rxa7 1-0

19)



Your response was: Yes, White can force a win.

This response was: Correct

White wins by building a Lucena bridge (shielding his king and queening pawn by using his Rook): 1.Re4 Rc1 [ 1...Rc3 2.Rf4+ Ke6 3.Ke8 ] 2.Rf4+ Kg6 3.Ke7 Re1+ 4.Kd6 Rd1+ 5.Ke6 Re1+ 6.Kd5 Rd1+ 7.Rd4 1:0

20)



Your response was: No, White cannot win by force.

This response was: Incorrect

White wins by first sacrificing his pawns to clear the seventh rank 1.f5 gxf5 2.g6 fxg6 and then playing 3.Rh8 (threatening to queen) to win the black rook after Rxa7 4.Rh7+ Kf6 5.Rxa7

21)



Your response was: Yes, White can force a win.

This response was: Correct

White wins because he can queen his passed pawn (or create another, unstoppable passed pawn) by playing 1.Rb2 Rxc7 2.Rb8+ Kf7 3.Rb7 Te7+ 4.Kd6+- Rxb7 5.axb7 and 6. b8Q

22)



Your response was: Yes, White can force a win.

This response was: Correct

White wins because the approaching white king creates a mate threat: 1.Qb4+ Kd1 2.Qd4+ Kc2 3.Qe3 Kd1 4.Qd3+ Ke1 5.Kg4 Kf2 6.Qg3+ Kf1 7.Kf3 e1D 8.Qg2#

23)



Your response was: Yes, White can force a win.

This response was: Correct

White wins because his approaching king suffocates the black king and creates an unstoppable mate threat after 1.Kg3 Qh6 2.Qe1 mate.

24)



Your response was: Yes, White can force a win.

This response was: Correct

White wins even though a queen normally cannot win against an h-pawn on the seventh rank, but here White can create a discovered check to approach his king close enough to create mate threats while Black queens: 1.Kg6 Kg2 2.Kf5+ Kf1 3.Qa1+ Kg2 4.Qb2+ Kg3 5.Qb1 Kg2 6.Kf4 h1Q 7.Qc2+ Kh3 8.Qd3+ Kg2 9.Qe2+ Kg1 [ 9...Kh3 10.Qg4+ Kh2 11.Qg3# ] 10.Kg3 and Mate in the following move: 1-0

25)



Your response was: No, White cannot win by force.

This response was: Correct

White cannot win because Black has the opposition; Black can therefore force a stalemate after 1.Kd6 Kd8 2.e7+ Ke8 3.Ke6.

26)



Your response was: Yes, White can force a win.

This response was: Incorrect

White cannot win because even though his pawn queens, the queen cannot win against the black h-pawn on the seventh rank because of a potential stalemate: 1.a6 h3 2.a7 h2 3.a8Q Kg1 4.Qa1+ Kg2 5.Qb2+ Kg1 6.Qc1+ Kg2 7.Qd2+ Kg1 8.Qe1+ Kg2 9.Qe2+ Kg1 10.Qg4+ Kh1 11.Qg3 Stalemate.

27)



Your response was: No, White cannot win by force.

This response was: Correct

White cannot win even though he can capture the black pawn; but his king cannot escape from the corner and gets stalemated after 1.h6 Kd6 2.Kg7 Ke7 3.Kxh7 Kf7 4.Kh8 Kg6 5.h7 Kf7 Stalemate.

28)



Your response was: No, White cannot win by force.

This response was: Correct

White cannot win because the black king has the opposition after White wins the black pawn: 1.Kd6 Kf7 2.Kxe5 Ke7! 3.Kd5 Kd7 4.e5 Ke7 5.e6 Ke8! 6.Kd6 Kd8 7.e7+ Ke8 8.Ke6 Stalemate.

29)



Your response was: No, White cannot win by force.

This response was: Correct

White cannot win because he cannot prevent the dancing black knight from defending the queening square d8: 1.Kc6 Nd8+ 2.Kc7 Ne6+ 3.Kd6 Nd8 4.Ke7 Nc6+ 5.Kd6 Nd8 =

30)



Your response was: No, White cannot win by force.

This response was: Correct

White cannot win because his bishop cannot control the square h8. The Black king can therefore prevent the white pawn from promoting to a queen on this square.

31)



Your response was: No, White cannot win by force.

This response was: Correct

White cannot win because after 1.b4 Bc4 there is no way to further advance the blocked passed pawns because of the opposite-colored bishops.

32)



Your response was: Yes, White can force a win.

This response was: Incorrect

White cannot win because according to the omnisicent endgame databases ("tablebases"), this position is drawn - one way for Black to draw is to sacrifice the bishop against the only two remaining pawns.

33)



Your response was: No, White cannot win by force.

This response was: Correct

White cannot win because the opposite-colored bishops allow Black both, to maintain a secure blockade of the passed pawn on the queenside and to defend all of his pawns on the kingside.

34)



Your response was: No, White cannot win by force.

This response was: Correct

White cannot win because his king cannot escape the black rook's checks from behind: 1.Kf3 Ra6 2.Ke4 Ra4+ 3.Kd5 Ra1 4.Kc6 Ra2 5.Kb7 Rb2+ 6.Ka6 Ra2+ 7.Kb7 Rb2+

35)



Your response was: No, White cannot win by force.

This response was: Correct

White cannot win in this well-known Philidor position in which the defender should keep his king in front of the opposing pawn and keep his rook on the third rank until the pawn advances to that rank. Then he should go to the far end of the board (the seventh or eighth rank) and check the king from behind: 1.e6 Rg1 2.Kd6 Rd1+ 3.Ke5 Re1+ 4.Kf6 Rf1+ 5.Ke5 Te1+ Draw.

36)



Your response was: No, White cannot win by force.

This response was: Correct

White cannot win because two pawns versus one pawn on the same wing is an insufficient material plus in this rook ending, an assessment that is also confirmed by the omnisicent endgame databases ("tablebases").

37)



Your response was: Yes, White can force a win.

This response was: Incorrect

White cannot win. The endgame with rooks and f- and h-pawn was analyzed to be a draw by Mikhail Botvinnik in the 1940s (with correct defense) and this position also is a draw according to the omnisicent endgame databases ("tablebases").

38)



Your response was: No, White cannot win by force.

This response was: Correct

White cannot win. This endgame with rooks and four vs. three pawns on the same wing is a draw because due to his perfect defensive setup (f7-g6-h5), Black can force the exchange of all his pawns if White tries to make progress.

39)



Your response was: No, White cannot win by force.

This response was: Correct

White cannot win. The endgame rook and knight versus rook is generally drawn, as confirmed for this position by endgame tablebases.

40)



Your response was: No, White cannot win by force.

This response was: Correct

White cannot win according to endgame tablebases. The endgame rook versus bishop is generally drawn assuming perfect play; the stronger side can only win if the defending king is trapped in a corner that is of the same color square as his bishop.

41)



Your response was: No, White cannot win by force.

This response was: Correct

White cannot win according to endgame tablebases. Even though the defense is very difficult and the stronger side therefore often wins, the endgame rook and bishop versus rook is generally drawn assuming perfect play.

42)



Your response was: No, White cannot win by force.

This response was: Correct

White cannot win according to endgame tablebases. The endgame rook versus bishop is generally drawn assuming perfect play; here, white cannot make progress because black is stalemated after 1.Ra8+ Bg8 2. Kg6.

43)



Your response was: No, White cannot win by force.

This response was: Correct

White cannot win according to endgame tablebases. Having the advantage of rook and pawn vs. bishop generelly leads to an easy win. However, in this position, there is no way to remove the black blockade.

44)



Your response was: No, White cannot win by force.

This response was: Correct

White cannot win according to endgame tablebases. The endgame queen versus f-pawn on the seventh rank is generally drawn because the black king is stalemated on h1 if White captures the black pawn on f2: 1.Qe3 Kg2 2.Qe2 Kg1 3.Qg4+ Kh2 4.Qh4+ Kg1 5.Qg3+ Kh1 6.Qxf2 Stalemate.

45)



Your response was: No, White cannot win by force.

This response was: Correct

White cannot win according to endgame tablebases. The endgame queen versus h-pawn on the seventh rank is generally drawn because the black king threatens to be stalemated on h1: 1.Qg3+ Kh1 2.Qh3 Kg1 3.Qg3+ Kh1 4.Qg4 Stalemate.

46)



Your response was: No, White cannot win by force.

This response was: Correct

White cannot win according to endgame tablebases. Two knights can generally draw against a queen if the king is near its knights because the two knights can set up an impenetrable fortress.

47)



Your response was: No, White cannot win by force.

This response was: Correct

White cannot win according to endgame tablebases. A queen has a theoretical forced win against two bishops in most positions, but the win may require up to seventy-one moves; this, however, is a drawing fortress position for the two bishops.

48)



Your response was: No, White cannot win by force.

This response was: Correct

White cannot win because Black can set up an impenetrable fortress along the fifth rank after 1. Kf4 Re5.