Puzzle of the week #90

Level: 
5-Queen
Chess Diagram: 

----b---
pq--p-k-
-p-pP--R
-P-P--K-
--rp----
--------
P-----Q-
--------

How often do you have the chance to use your King as an attacking piece? This normally happens very late in the game when most of the heavy pieces have left the board. There are certain exceptions and when you find one, that position is for sure special. Oliver Reeh is an International Master from Germany with a sharp eye for interesting positions. Today he offers you the chance to enjoy one of them (see diagram) from the game Jacob Aagaard - Robert Kempinski, Groningen open 1998. Oliver says: The King as an attacking piece on enemy territory was the theme in this game where White, a piece down, after 49... Be8 was facing a difficult choice.
Which evaluation of the position is correct?
A) the first player must give perpetual check;
B) he decides (wins) the game with 50.Qe4 ...;
C) he wins, but with another move.
Please provide a line to support your choice!
Total available points for this puzzle is 20. The answers will be published next week together with puzzle #91.

Puzzle #89 solution:
Karl's solution:
"a) In this position:
- White is up a pawn in advantage.
- Black's King is safer because there are three pieces attacking White's open King, while the Black King is heavily defended, and is not being attacked at all, except for a Bishop.
- Black has a Knight in the center of the board. Very useful.
- On the "a-" and "b-" files Black doesn't have any pieces, and White has two pawns and a Bishop on it. He can advance the pawns and threaten to promote later. This also holds Black at a disadvantage.
- Black has formed a battery.
- The White Bishop is supported by a pawn, in the enemy's fortress, and is attacking some squares like b8 or f8, so pieces cannot go there without being taken. This is a good Bishop, even though it's only on guard.
- White is under attack.
Summary: White's positives: 3 White's negatives: 1 Black's positives: 3 Black's negatives: 1
White's plan: For now, he is under attack, so the main priority is defense. White can throw a few counterattacks along the way, or maybe when Black is performing a 2 or 3 move procedure, White can seize that opportunity and attack, forcing Black into a defensive position. Attacking through the "a-" and "b-" file is the best idea, since that is like a hole right into Black's fortress.
Black's plan: Black is in attack position right now, and cannot let White gain a tempo. Getting advantage and threatening mate is the main priority for Black right now. The Black c8 rook will do for defending the gate between White and Black for now. Black should either attack immediately and win material, or prepare to launch the ultimate attack to either checkmate or gain a lot of material advantage, not to mention get into a better position.

Nobody managed to play as in the game and this is a bit surprising considering there were some good ideas presented as plans for both sides. The most striking things are how you guys chose to put the White King in the corner after being checked (this is bad since the White pieces are even farther away and not being able to provide any defence) and moving the White Queen all the way to "a6"; the White Queen was the lone defender and had to stay around doing its best to provide protection for the King. The game ended with the following simple line:
1... Qh5 2.Kf1 Nf4! 3.Qe4 Qg4 4.Bc5 Qg2+ 5.Ke1 Qh1+ 6.Kd2 Rxf2+ 0-1
Please observe how quick and easy Black mobilised 3 of his pieces for a final assault!

Correct solutions:
Karl - 18 points
Jeffrey - 16 points
Andy Q - 14 points
Rick - 10 points
Owen - 4 points
Humphrey - 2 points

STANDINGS

Karl - 78 points
Andy Q - 73 points
Rick - 70 points
Owen - 59 points
Jeffrey - 43 points
James - 17 points
Katerina, Alex - 10 points
Humphrey - 9 points
Wilson - 2 points

Comment: 

Complex endgame