Often in my games I'll have my knight pinned by my opponent's black bishop on g4. I think a fairly classic move is h3, making your opponent choosing between (a) Pulling the bishop back to its original diagonal, losing the pin, (b) pulling the bishop back to h5 and preserving the pin, or (c) trading with the knight.

Now, just to point out, I know you can (and I often do) do h3 before the bishop is there, so he'll never have the opportunity to pin you in the first place. Basically, is having the h3 pawn out slightly weaker than having it in?

The advantages I see are:

-Opponent's pieces can't move there, so you're gaining a space you can attack without losing any

-You can't lose from back row rook checkmates now

While only disadvantage seems to be that your 3 pawns in front of the king are now slightly less 'versatile', if that makes any sense.

What's the general consensus? Is it slightly weaker, or ok?

Your rating is 1995 

And I can weewee all by myself now too!!

I often find myself playing h3 when I just don't know what else to do. I have to play a move so I play a forcing h3/h6. When playing it for this reason it is just a lazy man's move. Unless you intend to play g4 at some point, which you probably won't when already castled kingside, h3 may be somewhat weakening. I would imagine it wouldn't be very good if your opponent hasn't yet castled, and you have castled kingside because he may decide not to go kingside and start a pawn storm.

Sorry, I guess you're right, I guess to technically be a pin, the piece behind the "pinned piece" has to be more valuable. I've changed it so it's definitely a pin now.

Chernev's book "Logical Chess Move by Move" is essentially a treatise against playing h3 and how it will destroy your position. His extreme view on not playing h3 has been analysed a little by Heisman and Nunn: http://www.chesscafe.com/text/heisman118.pdf. An interesting read.

Yeah, I didn't find it that bad if you take it witha grain of salt. Certianly his h3 stuff is a little over the top, but there are other interesting things that I got out of the book. It's nice for an introduction to strategy I think.

I'll take a stab at this (1400 here, please remember!).  In the position above, Blacks' light colored bishop is the stronger of his two.  So, I would say in the position above, it would be to white's advantage to attack the bishop.  If black agrees to exchange the light squared bishop for the knight, this seems like an overall exchange advantage for white.

Yeah, I just did some random common opening moves to get to this position.

Yes

Agree with post #4.