After 1.e4 e5 2.Nf3 Nc6, why are the Scotch (3.d4) and the Four Knights Scotch (3.Nc3 Nf6 4.d4) not better for White than they really are?

Question

After 1.e4 e5 2.Nf3 Nc6, if White plays 3.Nc3 or 3.Bc4 or 3.Bb5 and then Black answers with a bad passive move such as 3...d6, 3...h6, 3...g6, 3...Nge7, most often the best move for White is 4.d4.

After 1.e4 e5 2.Nf3, if Black plays the passive 2...d6, the best move for White is 3.d4.

But after 1.e4 e5 2.Nf3 Nc6, the Scotch (3.d4) and the Four Knights Scotch (3.Nc3 Nf6 4.d4) are NOT the best variations for White. 3.d4 and 3.Nc3 are each played only 6% of the time at GM level.

Why is that? What is causing this discrepancy?

If possible, I would prefer an answer with explanations in words, not long strings of moves. I am trying to understand the fundamental nature of the Double King's Pawn.

Answer 1

I don't remember where I read it, but I definitely read it in an opening book somewhere. It said of the Scotch: an early break in the center without preparation tends to dissipate, not generate, White's initiative. Another relevant principle is: a lead in development is a signal to attack.

The Scotch attempts to seize the center without a lead in development. That's why it tends to dissipate White's first-move advantage. (The same goes the Center game, 1. e4 e5 2. d4.) But if Black plays a passive move like 2...d6, then White has a lead in development, and hence the attempt to seize the center works well.

That one tempo really matters. If you give a chess engine the starting position of the Scotch, it'll usually give a small advantage of +0 to +0.1. But if you give

• 1. e4 e6 2. Bc4 e5 3. d4

or

• 1. e4 e6 2. Nc3 e5 3. d4

Then White's advantage grows to about +0.7-0.8. It's a difference of one tempo. The passive moves you're describing aren't actually wasted moves like in the two lines above, hence the advantage grows by less in those lines. But it illustrates how one passive move suddenly give White the scope to seize the center.

Answer 2

The Scotch has been heavily analyzed for two hundred years or more, and most of the resulting positions have been found to be equal without much prospect of further complex play. Kasparov revitalized the variation 3.d4 exd 4.Nxd4 Nf6 5.Nc3 Bb4 6.Nxc6 bxc6 7.e5 and the Scotch regained popularity for several years. After those variations were more fully understood, interest reverted back to the Lopez and more recently the Giuoco Pianissimo. Both tend to characterized by lengthy jockeying for position before embarking on tactics. In fact, this is often how opening fashions evolve. Popular variations are heavily analyzed for tactical resources. Usually, good answers are eventually found and interest shifts elsewhere. At the moment, the Scotch is going through a quiet period. Although this could change, it is quite possible that the Scotch attempts to grab the advantage too soon. The Lopez and the Pianissimo do not try for a quick advantage, unless Black does something daring themselves. They try for a small advantage in space and/or better placed pieces.

Answer 3

@Allure ‘s answer is on spot. The difference between Scotch and say Ruy Lopez is what happens after Black equalizes. With Scotch after Black equalizes, e.g. by acheiving …d5 favorably, there is no further objective chance for White to ask for more. But with Ruy Lopez, there is always this pull. There is still a lot to be played for. In other words, with Scotch if you do not obtain something out of opening then you have lost all White advantage. Same is not true for most Ruy Lopez variations.