In these days in which the main aim of organizers seems to be a ‘high category’, it’s worth remembering some of the reasons for organizing mixed strength tournaments. Besides giving local heroes a chance to beat star players, it can also lead to more brilliancies. It’s difficult to checkmate a 2700+ GM, but against lower rated players it’s a distinct possibility.
Here’s a brilliant win by Jan Timman from the days when mixed strength tournaments were still common. Black gets a dubious position out of the opening and is gunned down on the kingside in a cascade of brilliant sacrifices: