Grappling is just bad news for casters. 
If your Wizard ends up in this uneviable position (for example), and has little or no chance of breaking or escaping the grapple conventionally, what is your best-case tactics for escape? What verbal-only spells are available that can be effective against a grapple, and which are the best bets in your opinion?

If your Wizard ends up in this uneviable position (for example), and has little or no chance of breaking or escaping the grapple conventionally, what is your best-case tactics for escape? What verbal-only spells are available that can be effective against a grapple, and which are the best bets in your opinion?