This position has come up a couple times in my games recently. After I opened with the Scotch Gambit as White (1. e4 e5 2. Nf3 Nc6 3. d4 exd4 4. Bc4), Black played an interesting sideline. Here is the position after five moves, where Black has played 4…Bc5 (not too bad in and of itself, but not the main line) and then the interesting 5…d3.
Below is a video with some analysis, and in case you aren’t up for the video, I’ll give you the recommended moves from Stockfish and some ideas of why they are good.
Solutions to the Exercise
Solution 1: 6. Qxd3
After letting Stockfish run for about 20 minutes, it rates the simple-looking 6. Qxd3 as best. Although the queen probably isn’t best placed on d3, at least white is developing. The comp’s recommended plan after the likely 6…Nf6 is 7. b4, pushing Black’s dark-square bishop back to b6, then 8. a4 (with the threat of a5, trapping the bishop), where the following dynamic position is likely reached:
The above position is messy and complex, with dynamic chances for both sides. Stockfish evaluates the position as slightly better for White (+0.54 after running for about 15 minutes). It looks similar to something that could be reached from the Evan’s Gambit declined. GM Ronen Har-Zvi (once the best bullet player in the world) covers those lines in a video series that he made on the Evan’s Gambit for OnlineChessLessons.
Solution 2: 6. 0-0
Similarly good is simply castling. Stockfish still recommends the b4, a4 idea. The comp recommends 6…d6 for Black rather than the immediate 6…Nf6. I think the idea here is that 7. e5 would be a bit more dangerous given that White’s King is safe and that any Ng4 jumps would not come with an immediate threat on f2, given that White’s Rook would be covering it. Because Black lacks any tempo moves, d6 slows down White’s plan of e5, probably just enough for Black to get his King safe. Please add your own thoughts if you see other reasons for this.
In any case, a similar position is reached with a similar evaluation (+0.49):
Another interesting note about this position is that Black would be able to play Ne5 here, blockading the e5 square. In the position in Solution 1, of course Black would not have this move had he gone for 6…Nf6, but what if Black had played 6…d6 in Solution 1? Could he then play Ne5 (blockading the important square), or would have have to retreat the knight to e7?
In fact, Black does not have Ne5 here, precisely because White’s Queen is on d3, so now we see another reason why 6. Qxd3 is good for White (because it prevents the Ne5 blockade in this position). If Black tries Ne5 here, White can exchange knights, and then Black will lose 2 pawns and castling rights with the line 9…Ne5 10.Nxe5 dxe5 11.Bxf7+ Ke7 12.Ba3+ c5 13.Bd5 Nf6 14.Nd2 Re8 15.Nc4 Nxd5 16.exd5 e4 17.Qe3 Kf7 18.Bxc5 Bxc5 19.Qxc5 Kg8 20.O-O
These variations are long, but they give some insight into why certain moves are good and in which situations. In particular, Black has to be mindful of when he can blockade on e5, and White has to think about when taking on e5 would be beneficial.
Solution 3: 6. b4
So if White plans on this early Queenside expansion, gaining space with tempi, why not play b4 right away, instead of Qxd3 or castling? Stockfish evaluates this as a good move as well, only slightly behind the first two options. One interesting point is that Black has a nice resource in this line, playing Qe7 with tempo, before retreating his attacked c6 Knight:
White has several other reasonable moves on move 6, aside from the three solutions presented above (e.g., Bxd3, Bg5, Bf4). It’s a bit much to go over them all though. At least for me, I think the important part was to learn something about this line for White. Now I see why 6. Qxd3 is good.