Gridlock

Here's a game that threw me a curveball today.  My opponent seemed adamant to refuse all exchanges, which thoroughly locked up the board and prevented either side from making real progress.

Now that I'm ~1200 ranked I rarely find myself in a position where I flat out don't know what to do and can't seem to formulate a plan, but that did happen to me this game.  Several times I considered making a sacrifice (B for two P or so) just to open up the board in hopes that I might make progress, but never figured out an opportunity.

So I guess there's a more general question here after this match: If a sacrifice can't be immediately capitalized on, how do you know if it's a good one?

You should think about moving pawn on f4 at some point to attack closed center.