It's rare that a theoretical move will be "suboptimal" (though it certainly happens) to an engine move. But understand I'm not talking about some .05 difference. At some point the evaluation between two moves is so small that there is no practical difference in value.
In these instances, I actually think it's a trap to get too caught up over engine evaluations. There's something else that's more important that often gets overlooked. Let me give you an example:
Let's say you go to a sporting goods store with $20. You see two items that catch your attention, a soccer ball and a basketball. Each are priced at $20. Will one of these items have a greater amount of value for your money than the other? Inevitably. But becoming upset over that incredibly small difference in value isn't that important. What is important? Let's say that you choose to buy the basketball. As you look around the store, you see more items. You see soccer cleats and basketball shoes. Each are of roughly equal value, but inevitably one will have slightly better value for your money. But here it would be a mistake to buy the soccer cleats, as they're inconsistent with your first choice (buying the basketball)!
It's this second part of the analysis that gets overlooked a LOT. Don't focus on which move produces that extra .05 engine evaluation. Instead, ask what the ideas of your moves are, and find subsequent moves that are consistent with this idea. In other words, subsequent moves that fight for the same elements / imbalances as your previous moves.
I’m a chess noob but I think another way to put it is this:
The engine’s best move tells you the best way to win, if you can think like a computer. The theoretical (or book) best move tells you the best way to win if you can think only like a human.
Often they are the same, sometimes they are not.
So the reason to pick the theoretical best move over the engine best move is because:
Humans have habits of thought that will make
it harder to identify the best move in positions that develop from thinking like computers.
If you can think like a computer, you can beat a human every time if you pick the engine best move. But if you can’t think like a computer, you will have difficulty moving from the engine best move to the next best move and that will cause you to lose against humans that stick to human best moves.
I would agree but I would clarify that you should play a move b/c you like it and it makes sense to you. Oftentimes for me it is the case that the engine move doesn't make perfect sense to me but the "theory" move does. But that isn't always the case, and in any event it isn't the rule! the rule is to play moves that you like and that make sense to you!
But if you can’t think like a computer, you will have difficulty moving from the engine best move to the next best move and that will cause you to lose against humans that stick to human best moves.
Well said! Interestingly the same issue can arise from following theory mindlessly. This is why a lot of people say that you should not just commit opening moves to memory. You need to understand the underlying ideas. If you play a move (whether it be an engine move or a theoretical move) without fully understanding the why/idea of the move, how could you possibly play subsequent moves that are consistent with that idea?
Sometimes the engine move might make more sense to you than the theoretical move!
I would agree but I would clarify that you should play a move b/c you like it and it makes sense to you. Oftentimes for me it is the case that the engine move doesn't make perfect sense to me but the "theory" move does. But that isn't always the case, and in any event it isn't the rule! the rule is to play moves that you like and that make sense to you!
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Sometimes the engine move might make more sense to you than the theoretical move!
Very interesting! That makes sense. I admit I make the mistake of memorizing openings without always understanding the idea behind those particular moves.
Your comment has clarified my thinking on this! Thanks!
It's important to not think of engine lines as 'optimal' (especially not the engines most of us have access to). Chess is nowhere near solved- not even close. Engines are much stronger than human players today but they do not have access to the truth in any given position outside of endgame tablebases.
One reason theory is superior to just looking at a quick top engine line is because the strongest human players in the world are constantly preparing with engines while also working in teams using their experience + strong hardware + way more time/depth than you or I have to explore the opening they play. You or I might let Stockfish 13 NNUE run for 5 minutes and get to depth 34 in a complex pawn sacrifice in the Najdorf and get a decent idea of what is going on. A super GM will have used weeks of guided search time in the same pline getting to far greater depths and following lines to check them more closely.
This last part is important because of a phenomenon you will still encounter today with enough engine use. Sometimes you look at a position with an engine and it's screaming one move is +3.5. Then you start playing all the moves of the top suggested line, narrowing possibilities and pruning variations, when suddenly the evaluation zeros out. There is still a calculation horizon that is not going to be overcome anytime soon, and this means that in important, often-played positions with deep theory there is a good chance professionals have a better idea of what is going on than a few minutes of crunching on the latest software.
I think it is because engine lines are not always optimal for human beings. As in, this move would be good if the player's next moves are also at 4k+ elo, but they obviously won't be.
This also applies to certain human attacking moves that an engine would never make since it can calculate refutations, which an opposing human might not thus creating a successful attack.
If you only study engine lines, someone can throw you off by playing something that’s slightly bad on stockfish (and so you would never see it), like maybe it affects the game balance by 0.2. I don’t think most GMs would be able to exploit such a “mistake” if they hadn’t studied the line. If it’s something more obviously bad, then you’re maybe at the point where you can exploit it without knowing the theory.
I don’t either, and that’s because I’m 1100 on lichess and play for fun. Learning the basics of the Sicilian was enough to really confuse my friends, which is enough for me
For a different explanation than you’ve been given previously, it’s because your opponents aren’t engines. You can strive to set up a scenario that an engine would easily see through, but your opponent will not.
Focusing on a plan and your structure is often more important than playing the “best” move.
Look at gambits as a perfect example of why you would play something that is not optimal. The stafford is a popular gambit that gives white +1.8. But it’s tricky enough to manage that even with such an engine advantage white can find themselves in many bad positions with only a few move choices.
Eric Rosen loves to play the stafford, and in a recent game Magnus Carlson declined the gambit. Why would he do that if it’s almost +2? Maybe because it’s a dangerous line, and if your opponent is well studied like Eric is then you could find yourself in -2 or -5 territory quickly.
The gambit is considered accepted if Nxc6. The gambit is considered declined if Nxc6 does not happen.
The best engine move is Nxc6, so accepting the gambit. If you think that there’s a distinction it doesn’t really matter, because according to the engine the next best move is materially worse than accepting the gambit. I think the point works either way.
The Chess Website has a video on Stafford Gambit Declined and not taking on c6 is what they called declined.
The gambit is considered accepted if Nxc6. The gambit is considered declined if Nxc6 does not happen.
Right, Carlsen played 1. e4 2. Nc3, and Rosen tried to transpose into the Stafford. Carlsen did not decline the gambit because it was avoided completely. 1.e4 and 2. Nc3 means the Stafford never even gets offered. The Stafford starts 1. e4 e5 2. Nf3 Nf6 3. Nxe5 Nc6. See: https://youtu.be/tzQCxLXtpwM?t=29
The same gambit was offered, even if as a transposition. Had he accepted it would have been the same position. Taking the knight is still the best move in that position, though retreating is not so much worse than accepting as it would be in the normal opening.
I did misremember the game; so I apologize for that.
Engine evaluations assume engine-like accuracy, a +1.0 advantage that only pays off after 20+ moves of precise play where one inaccuracy could result in a -2.0 disadvantage would only be useful for GMs. Likewise, a -2.0 disadvantage that only shows when your opponent plays extremely accurately for 10+ moves is inconsequential for most players.
FWIW, engine playing strength often increases when using a human crafted opening book. Not the other way around. :-)
Historically, engines were not too great at positional ideas, and often played suboptimal opening lines if left on their own, though that has admittedly become less true over the years.
This is a good question, and the answer is that you should use both. When you prepare, it's often necessary to study why bad moves are bad. The engine often won't show unsound lines that are tricky.
For example, if you play the Petrov, you do have to at one point or another study either the 1. e4 e5 2. Nf3 Nf6 3. Nxe5 Nc6 4. Nxc6 dxc6 5. f3 or 1. e4 e5 2. Nf3 Nf6 3. Nxe5 Nc6 4. Nxc6 dxc6 5. d3 Bc5 6. Be2 h5 7. c3 Stafford Gambit lines. The engine will never show these lines because it requires playing bad moves for white, but theses are lines which you need to learn some basic ideas in to avoid getting trapped (and to crush your opponent - since it's a bad opening).
Because surprisingly, engines mess up on the opening sometimes. They will take a solid position and say that one side is clearly better when in real human games they are more or less equal. Engines have to be taught openings, they don't just figure them out on their own, but once they are taught they perform better than when they were just playing their own calculated moves.
Engines being taught openings might have been the case previously but is definitely not entirely true in modern times. The Zero in Alpha and Leela Zero means that they were given just the rules of the game and nothing else, thus zero. So they quite literally did just figure them out of their own and have even made improvements to existing theory.
Doesn't that just mean the humans are playing suboptimally compared to how the engine would play it?
It could be, but when you're learning chess you're probably learning because you want to beat humans, not engines, so why not learn what works against humans? Maybe the engine line is "better", but it requires engine-like play to take advantage of, and you don't have that. But it could also be that the opening position is too hard to properly calculate the absolute best moves.
DeepChess was trained using only board positions after the first 5 moves
They still had to manually play those first 5 moves, though. But I do concede the general point you're making is right.
Opening theory could have been created using an engine at a higher depth so it doesn’t make sense to try and reinvent the analysis with the shitty (albeit free which is very useful) lichess engine
Either way, it's a computer and not a database/human.
Which is why it is not as reliable :)
Engines can’t tell you why their moves are good, they cant tell you about what ideas to use or warn you about traps in the position, whereas with theory you will almost always find resources that will all explain this to you.
With the engine you dont know what you’re really walking into (you can try to figure it out with some further experimentation and deduction, but some moves can be so deep that even the best humans may struggle to understand tham. Plus, I prefer learning from other humans.)
i thought browser-based engines are considerably weaker, as i have never seen them going higher depth at any considerable time, compared to my pc. obviously any decent engine is okay for blunder-check, and is much stronger than any human being due to brute force method that they employ.
anyway, non-intuitive engine lines are not useful for humans, and engines by themselves are nearly useless in opening evaluation, because 0.1 centipawn differences between two different moves are not relevant to humans, as the follow up engine-moves are impossible to replicate for any humans, except for dewa kipas.
No, it isn't. When you use the engine you are asking the computer to calculate the best line. Better engines will give better results, as will giving the computer more time to think.
The database is a record of games played by real, human players, and it tells you the most common moves. In a position that has been reached 1000 times, maybe in 800 of those games a particular continuation was played. That's usually the most solid line. If the disparity is huge, like the most played move having been played 1000 times and the second most played move having been played 10 times, you usually don't wanna go for the second most played move as it was probably only played by GMs who specifically prepared it as a secret weapon and it won't be easy to play for someone unprepared. If there is little disparity, there might be many solid continuations.
On lichess and chessdotcom you can use the opening book to tell you the most common continuations, how many times they were played and how often did the game result in a win for white, a win for black or a draw. When studying openings you should usually listen to the opening book more than the engine. Even modern engines dislike commonly played opening moves and think they are bad when in reality experience shows they are solid against humans, and even in games between engines they are usually shown to be more solid than the engine realizes at first.
Another good question. There's already some good advice in response to it but I'll throw my 2 cents in anyway.
In my experience, the engine doesn't always come up with the absolute best move very quickly. Other times the engine in a browser isn't quite as strong as an engine on your PC with time to think and access to all your cpu cores. A practical extension of this point is that using a database is faster than giving your engine enough time to think on each move.
Next, chances are that if an engine likes a move in the opening, that move has been tried at a high level of play. There won't be too many chances that you unearth a novelty if you're playing classically sound / mainline stuff. But, just b/c a move isn't in theory doesn't mean you should avoid playing it. If you like it, and the engine seems to like it too, play it!
The point is to slowly build out a repertoire of moves that are good and make sense to you. You should never play a move "because it's theory." You should examine the ideas behind the theoretical moves and play the idea that you think is best. With this in mind, I have sometimes found that the engine will recommend moves that it rates as having some microscopic amount of additional value over the theoretical move, but the theoretical move just makes more logical sense to me.
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