Is it possible for a database to win against a player? Sounds weird, but if both sides are following book/database moves, and one side's database is more comprehensive than the other, this just might occur on rare occasions.

Is it legal? In correspondence/online chess in Chess.com, definitely!

Is it ethical? Well, if the other player is informed yes. If only one side is following a database, and the other side is not aware of it, or is not informed - may not be. I had informed my opponent through chat, (albeit a bit late), so I am in the clear...

One mistake/blunder was enough to lose. You be the judge.

Hi! I think it is of no use to follow blindly a database. Because we are not the machine but human we should use our intelec to play a game and win that will give u satisfaction.

TigerSAMIR, please point out to me where the original poster said that he blindly followed the database. Oh, you can't?

I have lost to essentially a database here on chess.com. I occasionally use opening books. My opening prep left me in an equal position. I tried a line that was fine, but in my opponent's database. When I faltered, he had the solution right in front of him.

I don't think there is anything ethically wrong or even questionable about it. Anyone who plays correspondence style chess should be aware of the rules and the fact that many players use resources for the opening.

No, nothing wrong. I have posted here where I followed a known game to mate, another user posted a game where he won with a conditional line, from move 1, to mate :)

Personaly I view correspondence chess as a learning tool - as a way to increase my chess understanding and thus also to improve my OTB play. The chance to use reference material is great in this respect since it allows me to do usefull opening study during the games.

Using databases doesn't equate not using your brains. First of all, most games eventually leave all databases and secondly even when still in the database you still need to make choises between different database moves based on your own analysis. And of course at some point you may find that any database continuation doesn't satisfy you and need to devise your own plan - after all not all the games in the databases are played by strong GM's and even those that are may sometimes contain relatively easy mistakes.

Actually, the site rules allowing reference material but banning engine use are just right for me and one of the reasons I play here instead of some other places allowing engine use. I can even understand people who also like to use engines as long as they do it somewhere else - there are many places to play cc where computer use is allowed.

TigerSAMIR, the purpose of database, as Loomis pointed out, is the same as a chess book - to help learn and improve one's chess. "Blindly" following database is done by newbies only, who do not understand the significance of each move.

echecs06, databases are learning tools which give us the chance to study the lines played by masters in the past. It is like studying hundreds of masters games for opening phase, only much faster. The trick is to play each line out 8-12 moves forward along each branch to give an idea of the complexities of the current position. As it is not unwise to use a calculator, rather it is unwise not to use one when we are given the chance - similarly it is unwise not to avail oneself of every learning tool that are freely available and allowed.

I find it much easier to learn and remember an opening or an opening variation by using a database during a correspondence game rather than studying a book. And one should not try to "blindly" follow a database  - one should try to understand the moves, and then select on one's own the line that best suits one's style.

LaskerFan, what database do you use?I will understand if you don't want to tell.

@CHCL, heh heh heh

Some messages are better conveyed unspoken

 I have won many a game when my opponent deviated from the book move, but the db doesn't tell me how to take advantage of it. In the above game it would not have taken a genius to figure out what to do when black erred because the situation was critical. The fun of correspondence chess is studying WHY this move or that move is the best. When my opponent deviates is when I study the situation hard knowing that maybe, there is a strong continuation to be found. But sometimes there isn't. It's just that your opponent made a decent move that isn't in any database. But if you study the opening through several games you will have a good chance of being able to figure it out. You learn a lot that way. I am playing a game now where I deviated on move 4! I think it was sound if not necessarily forceful but it is now up to my opponent to figure out a refutation.  What great fun! (game in progress-no telling!)