Monday, 1 April 2013

Drawing with Vancura Position

So far in Rook ending we have discussed Philidor Position (Drawing Method) and Lucena Position (Winning method), today we are going to discuss Vancura position(Drawing method).

Position's characteristics :

  • Strong side is having an extra pawn and that is rook pawn.
  • Pawn is not beyond its six rank (Pawn is on h6 in diagram)
  • Strong side rook is tied up in defence (in front of the pawn, Rook is on h8)
  • Defender rook attacks pawn from the rank (Rook attacks pawn from c6 in diagram)
  • Defender king must be on other-side of the board in the corner (in our case King is on b7 or a7) so that stronger side rook can not check the king to promote the pawn or can sacrifice the pawn in order to set up skewer.

Drawing Method :

Key :Do not allow your opponent to support pawn with the help of king.

1. Kg5  Rc5+
h7 was not possible because of Rh6! 2. Kg5  Rh1 3. Kg6 Rg1+ 4. Kf7 Rf1+  5. Ke7 - Ra1 draws, Please not that defender king must be in corner(b7 or a7) if defender Majesty is on c7 the white can win sacrificing pawn with Ra8! if ....Rxh7 then Ra7+ wins or Defender king is on b6 then Rb8+ and can promote the pawn to queen.

2. Kf6 Rc6+ (Important square in Vancura position for defender rook)

3. Ke5 Rg6 (attack continue through 6th rank on pawn)

4. Kd5 Rc6

5. Rh7+ Kb6 etc

Summary : Pawn can not be advanced because defender rook gets behind the pawn and Stronger side king cannot  advance because of checks.

For better understanding and clear picture of the position lets go through some examples.

White to Move

1. Kb5 Rf5+
2. Kb6 Rf6+
3. Kc5 Rf5+
4. Kd4 Rf6
(4... Rf4+ ?? 5. Ke5 Rf6 6.
Rg8+ And wins)
5. Ke5 Rb6
6. Kd5 Rf6
7. a7 Ra6

Black to Move

1... Rh1
(1... Rg1 ? 2. Kf5 Rh1 (2... Ra1 3. Ke5 winning) 3. Ra7+ Kh6 4.
Rb7 Winning) 

2. Ra7+ Kg8

Drawing Zone
In 1950 Peter Romanovsky published below drawing zone

In the position, with Black to move ; Black can draw by reaching Vancura Position only and only if White king is on one of marked square otherwise white wins

Examples of Drawing Zone