The Pawn Poke
Be it annoying, mildly painful, or downright inappropriate, the pawn poke is a key theme in understanding pawn structures and color complexes. Once mastered, your opponents will feel like they are locked in a room with a deranged 5 year old waving a stick around.
The pawn poke is characterized by the exposure of an underlying weak square(s). We create pawn tension that can only be resolved by the opposing pawn relinquishing these key square(s) in the position. The poke is most effective when the poked pawn is unable to garner support from a neighboring pawn. Here's an example:
Now for the real stuff. This guy almost drew Capablanca, but alas he got poked...
Here's another example where, white voluntarily weakens his structure. It's important to recognize when you push a pawn that it weakens a certain set of squares. There's a famous phrase, something along the lines of "Be careful with pawn moves, because they can't go backwards".
Now we will look at 2 examples from a true master of poking people. (with pawns) Mr Tigran Petrosian.
Note the Shape of Petrosians right hand...