If to win, you need to be the one that doesn't take the last counter then the answer is to change 1-1-2 to 1-1-1 so your opponent takes 1, reducing it to 1-1-0, and then you take 1, reducing it to 1-0-0, and your opponent takes the last one, letting you win.

If to win, you need to be the one that doesn't take the last counter then the answer is to change 1-1-2 to 1-1-1 so your opponent takes 1, reducing it to 1-1-0, and then you take 1, reducing it to 1-0-0, and your opponent takes the last one, letting you win.