Using Databases Well

How do players use Chess.com's Explorer and other resources to get an advantage in the opening? Do you play the percentages?

In the Flick-Knife Attack, for instance, 9.a4 is the main line. In The Modern Benoni, David Norwood says it is the correct move. But, two moves score slightly better. Are these worth considering?

I played 9.Nf3 last spring and beat a higher rated player. See http://chessskill.blogspot.com/2013/07/busting-benoni.html for detailed game analysis.

I am less interested in the Benoni than in the ways players use the Explorer and other database resources.

What resources and methods work well to accentuate the positive aspects of correspondence play, including winning more than losing? What methods of using the Explorer lead to failure in the game? What methods deprive the game of its appeal?

There should be no question that using databases well requires lots of mental effort and more time expenditure than playing without these resources. 

I have raised these questions before, such as at http://www.chess.com/blog/Ziryab/playing-with-databases.

I'm always open to some intelligent discussion concerning databases instead of the eternal newb questions about why they are allowed or whether they should be.

You have to approach your book with criticism. I have a book which is in general very good but I have found some doubtful lines in it which you should avoid. So even equipped with a book you have to do your homework. Nothing is guaranteed.

I won't use a move that I don't understand (anymore).   Yes, I realize that sometimes to understand a move requires research and I do that, but if I don't have a clear understanding of where a line is headed and why,  I choose something else.  I'll also often choose the simpler of continuations if the resulting complications look beyond my ability.  And yes, I do use another database that includes nonmaster games because often the "favorite" move makes more sense to me.  And sometimes I just say the heck with it and play whatever I want; those are usually the games I get in trouble with but at least I tried something of my own.

As far as the percentages are concerned: it is possible that a move scores very well in general but there is a refutational counter move which is found by only a few and therefore can not influence the total winning percentage in a meaningful way. You have to be aware of that and not play a move solely based on its winning percentage.

Use the database to reach positions you understand better than your opponent does, even if that means playing the main line (if you understand it).  Don't try to become an expert in all openings at once, but do learn a few openings.

For club players, databases are double-edged as mis-reading the %ages is surprisingly easy : for instance, there can be razor-sharp tactics in positions/lines that innocently read "45-50%" on the win-loss column.

I've seen positions where white has a 30% winning percentage at the Master level but it "required" black (Masters!) to play very accurately to bust this line for White.  Masters playing black probably have the tactical acumen (or they might have even booked it up!) to wade through these waters safely and come out with an advantage, but the regular 1800 club player? Give me a break! :)

   What about gambit lines that club players love? Masters play them less and the statistics are thereby less useful or even worse, misleading!

Every scalp I've ever had in OTB against a 200+ rated player (including experts) was with what GMs might consider "broke-a##" openings but I won those because I gave my higher rated opponent plenty of opportunities to play these positions wrong with a less than 60-minutes per game time control. 

Tim McGrew wrote a beautiful story-like article on this behavior : http://www.chesscafe.com/text/mcgrew20.pdf

Worth a read if you are hung up on database stats! :)

To summarize : if you are a club player, databases can "suggest" things (if you are looking for ideas!) but you have to roll up your sleeves, try out the lines and think for yourself, weighing the practical considerations of risk, time management and familiarity of these lines especially given that the opponents you play are rarely the people contributing to the statistics you see in your favorite online database!

How do you balance making moves that you understand with trying new moves that score well with the intent of practicing unfamiliar positions? Is correspondence chess primary, or is it training for OTB?

I normally think of it as training for OTB, but after a bad tournament this weekend, I find comfort in my inflated correspondence rating on two sites.

I agree with most of that in principle.

But, I'm a sucker for the move that looks slightly odd, or even downright bizarre. If there's not an obvious refutation, most likely I'll go that way.

Hell, it's a game, and I'm supposed to have fun. right?

I enjoy the effort to refute the percentages in Chess.com's Explorer when I think that's how my opponent is playing.

Having reference to Chess Informants sometimes assists this process.