I've been analyzing classic "romantic" games using Stockfish with multipv (showing the top 4-5 lines rather than just the best move)

1. Morphy vs. Duke of Brunswick (The Opera Game)

https://lichess.org/study/xAo78qLb/truC6WoM

16. Qb8+.

This is viewed as Morphy doing a stylish Queen sacrifice

But if you look at the MultiPV:

Qb8+* leads to forced mate.

Qc3 or Qb7 drops the advantage significantly.

Qb5 actually allows equality

If he had played anything else, he would have been imprecise. It wasn't a gamble

2. D. Byrne vs. Fischer (Game of the Century)

https://lichess.org/study/UZlSqSLA/Ku9M59je

Fischer plays 17... Be6, leaving his Queen hanging.

Standard narrative: "Fischer offers his Queen for a mating attack!"

Engine reality: 17... Be6 is the correct move. Trying to save the Queen actually loses the advantage.

Byrne taking the Queen (18. Bxb6) was a massive blunder. The engine actually wants Byrne to ignore the Queen and trade off Fischer's Knight on c3. He ends up with a Queen stranded on a3, a total spectator

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reassess_blind 12 hours ago | parent | next [-]

Qb8+ is a fairly obvious mate in 2. I don’t think anyone views it as a gamble.

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firasd 11 hours ago | parent [-]

Right. So I guess that's my quibble with the term sacrifice (shared by Rudolf Spielmann)

But what's interesting to me is the counterfactual like outside of these 3 queen moves he would have lost the entire advantage. So it was like a tactical shot like capturing the golden snitch in Harry Potter

	▲	reassess_blind 11 hours ago \| parent \| next [-]
		Sure, I get what you're saying. It's still a sacrifice, but the compensation is just mate in 2, so the there's no real "sacrifice" here. That being said, any sacrifice that doesn't guarantee a better (or at least equal) position isn't a sacrifice either, it's just "hope chess", aka a bad move. In Blitz or Bullet you can make the case for a "bad" sacrifice for positional complexity and putting time pressure on your opponent to make accurate defensive moves. In the Opera game, Black just played a poor game start to finish. Giving up the bishop for the knight, pushing the B pawn while the king wasn't castled.
	▲	le-mark 9 hours ago \| parent \| prev [-]
		I had two “brilliant” moves in one chess.com game today. One was a bishop sacrifice that would have led to mate in three. The other was a queenside castle that the engine wanted me to do sooner. I suck at chess, although I did see the bishop sacrifice as the right move. The engine rated me at 1500 for the game.

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Trufa 12 hours ago | parent | prev | next [-]

Most of the times they mean the amazement of just even considering that move a couple of moves ahead and not discarding that branch.

But yes, a true gambit could be considered something that's objectively bad, but humanly makes sense.

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TZubiri 13 hours ago | parent | prev [-]

This is a common theme, gambits are such depending on what your level and calculation depth is.

The queen's gambit opening (almost inarguably a gambit as it is part of a well accepted name of a second move), really isn't a gambit in the sense that you can always recover the pawn, however it is a gambit in the sense that you temporarily give it up.

If we were particularly short sighted, no doubt, responding to an early white bishop threat on g5 or b5 with a knight on f6 or c6 would look like a gambit, as we are sacrificing the knight, but lo and behold, we regain the minor piece afterwards with xf6 or xc6!

The distinction would be whether the gambit or sacrifice is solid or refutable. But it is in both cases a sacrifice.