Scotch Four Knights... What would you do after this move?

I agree with fiveofswords. I have said this as pertaining to the principle: "The best move is a position is only the best move you can find." If you are in a position which is "better" but where it is extremely difficult to find the best move, go with the inferior position where it is easier to play.

Remember that, at a very practical level, chess is only a draw until your opponent makes a mistake anyways. A very real facet of chess is to play for positions where you won't make mistakes and your opponent will rather than go for positions that win with best move order.

Guess what, with best moves, everything mentioned here draws at move 5. 5: d5 is a draw, 5: Bb5 is a draw, 5: dxe5 is a draw. There isn't a win for white.

So the only thing left to do is to enter the position where it is easier for you to find the right move than it is for your opponent. Your opponent has to make a mistake for you to win, and it's important to recognize that. Don't pretend like white has a forced win at move 5, just force your opponent to think as hard as possible and make the game flow as easily as possible for you.

pfren: At this point I believe little of what you say beyond the obvious. Just about everything you say is supported only with hand-waving and "if you're not smart enough to agree with me" disparagement.

Players far better than pfren have been proven wrong in their dogmatic harrumphing about opening lines.

The argument, again, is not whether 5.d5 is a killer move that puts Black on the ropes, but whether 5.d5 is a playable alternative for White at that juncture.

So far nothing you've said demonstrates 5.d5 is unplayable other than it goes against your idea of what should be played in such a position.

I let Stockfish run to 44 hours and 5.d5 was still the top choice. Which hardly means it is the best move but it's worth consideration. Maybe it's a problem with Stockfish's programming. Or maybe it reflects a blind spot in current master intuition with pfren as an example.

5..Nb8 also remained Stockfish's choice for Black. It would be interesting to compare that line with 5..Ne7. I looked into it briefly and it seemed Stockfish was "concerned" about the pin Bg5.

Fiveofswords makes a perfectly fine argument for preferring a line one understands well over a line which might be favored by a computer engine or current GM practice for that matter.

The queen trade and textbook grind-down in that Four Knights position was one of the first things I thought of.

FiveOS also makes a good point that ThrillerFan's advocacy for 5.d5 might relate to his familiarity with the French Advance variation.

Stockfish 6 on 1 CPU with MultiPV set to 7 isn't going to get the best results.

Letting an engine run for 44 hours straight is not the best way to determine what the best move in a position is.  You need to fill the hash up with several variations into the future then return to the start position to see what it thinks.

SK5: I'm not trying to get the best results. I'm just offering a data point that 5.d5 is a playable alternative.

So far I've read nothing substantial to the contrary.

Using a chess engine isn't the best way to determine what the best move on move 5 is...period. I agree with pfren on that much.

But a chess engine is a reasonable way to get an idea for plausible -- not necessarily the best, but plausible -- moves in an early position.

Of course there is an art to setting up the hash tables, threads, and so forth. I have written a UCI interface to talk to a chess engine and so it can "grade" my Guess-The-Move games, so I have some idea of the complexity there but I wouldn't call myself an expert.

5. d5 is a legal move that doesn't lead to a forced loss for White, so sure it's "playable".

By playable I intend something more like a "good enough alternative, though not necessarily the best."

I'm trying to avoid pfren mischaracterizing my position then ridiculing it, as he frequently does.

pfren claimed 5.d5 is "positionally blind." I understand resolving the central tension immediately like that is generally frowned upon these days. Which is fine. That's part of the accumulated intuition which makes a master or grandmaster.

But those intuitions, valuable as they are, may not always be right. As chess has advanced, more and more exceptions are found. Moves that were previously discarded because they were considered positionally blind or some equivalent have become standard master practice.

5.d5 might not be such a move, but it strikes me as worth investigating. I understand that it offends pfren's positional sense, but that's not sufficient reason to close accounts on it forever.

BTW, a good trick I learned while writing the UCI Guess-the-Move program was to analyze the game backwards so when the engine evaluated a position it could make use of the evaluations already stored in the hash tables -- for the reason SK5 mentioned in #47.

I am not a fan of this position to be honest.

Which is to say I do not know how I would continue.

I guess I would have to think about it.

d5 just gives Black c6 and f5 breaks which are very powerful, and White is in no position to stop them because he is not well developed and he has no breaks of his own.

pfren: Of course.

However I will post as I please and take your inability to respond cogently in my favor.