How Morphy Took Down the Isolated Queen Pawn
It's interesting how few players seem to want to battle against the isolated queen pawn (aka the IQP or isolani). This statement is mostly based on anecdotal evidence: I've had at least a couple of students tell me that they just don't play against it. But I have a hunch that the sentiment is pretty widespread. Based on these views, it would seem as though obtaining the IQP is a forced win! Of course, this is far from the truth.
The holder of an isolani (let's say it's white here who has the IQP) generally has more active pieces thanks to the (half) open c and e files, possible knight outposts on e5 and c5, and the slight space advantage that the pawn confers; plus, white has the potential for a dynamic push of the pawn to d5, often as a sacrifice. It would seem that white therefore should (by the will of Caissa!) possess strong attacking chances with an isolated d-pawn. Sometimes this is true, but the realization of those attacking chances is based on a struggle of ideas rather than a given. Of course, the placement of the pieces and how they are maneuvered is essential to whether the isolani ends up being a "good" one or simply a target.
Indeed, Anand, a dynamic player, has willingly played against it many times. In defiance of popular conception, he was able to gain active pieces and, what's more, often became the aggressor! Karpov also has handled the pawn structure masterfully. Though Karpov was known as a solid defender, so this fits into the stereotype of the structure. But would you expect that one of the most famous attacking players of all time, Paul Morphy, would grant an isolani to the formidable Adolf Anderssen in their high-stakes match? Believe it, because he did; Morphy defeated Anderssen handily in that game, then went on to score an 8-3 victory in the match.