Tactics: Perpetual or Not?

Positions with Queens and Rooks on open boards can be very challenging to calculate: there are usually several candidate moves and there are long checking sequences to analyze. In this week's game, Tom Bark - Mark Plotkin, Ontario Open, White has just blundered a piece and is now trying for a perpetual. Can Black win? 

Solution: see the game below,

 

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 Round:  Result:

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From the game:

Tom Bark - Mark Plotkin
2015 Ontario Open
(16.5.2015).

The complete game, along with others annotated by IM Tomas Krnan and FM Shiyam Thavandiran will appear in the next issue of Chess Canada, the CFC's online newsletter.