Why isn't copying from an opening explorer during a game considered cheating?

I recently read that it's a fairly common practice for people to use an opening explorer as they're playing online chess and copy the moves from that against an opening they don't know. Recently when I was playing the Budapest my opponent paused for several minutes after I played 2...e5, then they proceded to quickly and correctly play one of the main lines against it. I suspect during that pause they may have looked it up in an opening explorer.

How is this any different from using a chess engine? In both cases the person is not making their own moves, but copying them from a computer. Maybe the only reason this isn't considered cheating is that it would be so hard to conclusively detect and/or stop?

Because correspondence chess has always allowed the use of books.  The old joke back in the postcard days was that the player with the bigger library would win.  Our "online" games simply are a digital version of an old traditional way of playing chess.  Yes it is "training wheels" chess for many, although the elite players are trying to mold each game into a masterpiece.  Many previous threads on this....

technically it isn't cheating there are no evaluations on any of the move in an online database. it doesn't tell you what is the best move or what is a good move. all it really is, is a collection of games organized to see how many players played x move in y position. which basically means if you copy off the game explorer you may play a losing move or maybe just a bad one.

The old joke above has rarely worked for me. Just copying moves out of books or DBs with little or no understanding of why they were played is probably similar to copying text in Cyrillic or Chinese without being able to read it. 

Chess engines very much tend to give good moves or the best move.

Not so for game explorer.  Very often it will give poor  moves or maybe 3rd best move.  So if you just copy the moves on game explorer--you may be in for a surprise! 

People are saying opening explorers give no evaluations, but on the ones I've seen they have percentages for each move alternative that show how often white or black win going down that particular opening path.

 I'm still not completely clear on what the "ideas" are behind the openings I've learned and play often, and I never use an opening explorer. I just thought the idea of an opening is to get your pieces out effectively. When people say the idea or plan of an opening do they just mean the "themes"? Like in the Budapest gambit there are themes of being active with your pieces and using the iniative, the rook lift possibility in the Adler variation, playing against doubled isolated pawns in one of the Rubenstein variations, etc? Or is the "idea" of an opening and the themes different?

But it also shows how many games are in the database for each move. So the person could just take the most played move with the highest win percentage for their side. Like the explorer at Chessgames.com for example

http://www.chessgames.com/perl/explorer

Ideas and themes are more or less the same as the opening "plan". Which themes to execute depend on your opponent's play and your judgement.

Taking the highest win percentage move doesn't do much. Even allowing for the law of large numbers and regression to the mean or whatnot (translation: assume the database is somewhat reliable) that move could lead to an incredibly technical endgame or a pyrotechnical tactical mess, and you (or your opponent) might not be able to navigate that well. What works for many people lots of the time may not be good for you in a game. Knowing which moves lead to middlegames you can handle is more important than bandwagoning.

"All openings are playable but they are not all playable for you." - GM Michael Adams

I use game explorer for ideas of what sorts of moves are typical for a particular configuration.  I'm not trying to "cheat."  I'm trying to learn.

After a few go-rounds, I've absorbed some of the typical openings and typical responses to those openings.  I'm learning some basic, very basic opening patterns maybe.

I still have the middle game and possibly end game to deal with on my own.  And I still have to choose from the possible moves suggested by the explorer.  And yes, sometimes it can lead you astray -- you still have to use judgement.

Also, the database isn't that big.  Often it has maybe one or two games for a particular configuration -- hardly a definitive guide to what the best move should be.

I use it as a resource, a repository of ideas.  I'm using opening explorer to improve, to learn.

That's a far cry from having an engine run the game, and spit out the "optimum" move for me.  If I was doing that, I'd have a lot better chess rating than the crappy 1026 rating I have now.

@Jadarite is right.  If your opponent is making better moves, that should only help you to learn.

If you know your opponent is playing the most common choice in Opening Explorer, just steer them into a line that has been recently refuted.

I think using an opening explorer really gives you quite a big advantage.

Some of the posts above are about blindly playing the recommended moves without understanding the strategies of the opening and I agree that doing that won't help much.

I think the benefit is more subtle. I've had plenty of irl games where I knew the general plans and key moves to look out for, but messed up some move order or forgot some in between developping move before starting the real plan.

For example, I play the kings indian as black, something I haven't encountered in years is the four pawns. Now I have studied some Na6 line against this before, but since I haven't played this in ages I only remember the basic ideas on it. You play Na6 followed bij e5, sac a pawn for active pieceplay, queens get traded, you develop with threats and get counterplay. If I were to play this line right now, I think I'd lose quickly for not knowing the exact moves. with an opening explorer I'd be fine.

I also think rare lines lose value. As a kid I used this line in the italian: 1.e4, e5  2.Nf3, Nc6  3.Bc4, Bc5  4.c3, Nf6 5. d4, exd4 (normal so far) 6.e5, it's quite tricky for black unless you know about 6...d5. How many people are comfortable against 1. e4, c5 2.b4? some kind of opening database really helps you in those situatons I think.

What Rigamagician and Estragon are saying is that the top players catch on and quickly stop playing discredited lines.

The latest greatest refutations barely make it into the database because whoever uses cutting-edge refutations tends to play opponents who also know them, and won't play the discredited lines.

In other words, top players barely give their opponents a chance to use the latest refutation.

That's why the newest, best responses barely register a blip in "game explorer" type databases.

To summarize: while some of the latest refutations may show up in the game explorer database, they won't be among the top choices, statistically, because people who know the latest refutations tend to play opponents who also know them.

If a line is "discredited," it's just that: defunct.  Why would a top player continue playing a discredited line?

So in fact, the latest refutations "fly under the radar" of a "crowd-sourced" tool like the game explorer.

Q.E.D.

(I think :)

@Jadarite wrote:

    "I am sorry you lost me."

I rewrote my post.  I tried to make it clearer.

And yes, this is largely an issue for really top players.  But the "Game Explorer" is supposed to be comprised of "top rated" gameplay, no?  So it applies here.  The Game Explorer doesn't contain all of the games played by scrubs who suck at chess (such as -- cough -- myself).

For crappy players such as myself, this is really not an issue.  I'm just trying to learn a few opening uhm, patterns.  Or something.

Ah, force strong in this one. Enemy king Darth Vader you can kill, but first, enemy stormtroopers destroy you must. To become king, destroy the pawn you shall. Learn my young padawan

So wait, you can or can't use opening explorer etc. in Live Chess? I'm confused. Don't really care for Online Chess.

This is why I almost only play blitz...

Online chess is a good chance to study and learn and using Opening Explorer helps you to learn. If you want to know the strategy and tactics involved in the  line you are following you can go to the games in the database and play them out. This is allowed because books and notes have traditionally been acceptable in postal chess.