I don't work on my openings as much as I'm sure the very top GMs do (mostly because I have so many other areas of my game to work on), but I do try to spend some time every week looking at some opening line in depth.
Back in August, in preparation for the Montreal International, I had spent some time on the Semi-Tarrasch Defense in the Queen's Gambit Declined. The Semi-Tarrasch is not very popular these days, and I had never faced it before, but I wanted to look at it for a couple reasons: (1) there was a possibility of facing it in Montreal and (2) I had never really studied the typical patterns and ideas that arose in the very characteristic middlegames.
Probably the most famous game in the Semi-Tarrasch ever is Polugaevsky-Tal, USSR Championship 1969. Here's that game with some light notes:
Fast forward to November, when I had the white pieces against IM Leonid Gerzhoy. I wasn't quite sure what to expect from Gerzhoy, as while I had seen that he had played the Semi-Tarrasch to good effect a couple times, he seemed to favor the Nimzo Indian and Ragozin. As it was, he chose the Semi-Tarrasch and I had a chance to try and show what I had learned from my study back in August.
Question 1: What would you play for White after 18...h6?
Question 2: What would you play for White after 27...Re7?
Question 3: What would you play for White after 34...Bc8?
Here's the entire game in one viewer: