At some point I submitted a baseball question. It was rejected for being too specific. I had no issue with the rejection. Since I had no clue how to correct the question, I forgot about it. Recently, I was issued a challenge to submit a question. Without realizing it, I submitted the same question but worded differently. It was accepted but modified. The modification made the question even better than my second version (which wasn't too bad). How do I know who modified the question, as I would like to thank them?

You have a choice of three! Unlike the system for quizzes, we cannot go in and have a look at which editor placed it online.
This might work -- send a correction note to yourself on the baseball QQ. The correction-screen will show who placed the QQ online (on this side of the fence; on the screen visible to editors).

I will give it a try. Thanks.