Month 1 Annotated Games - Drazic vs Anand

In the notes after 3.Bh4 the consequences are stated that on h4 the bishop controls 5 squares, whereas on g5 the bishop controls 8 squares.

Actually, this confuses the concept of mobility (defined as all legal moves of a piece) and control (computed by counting attackers and defenders  at the square of each legal move).  

Correctly stated, the comment should read "Bh4 remains unprotected and it controls one square comparing to Bg5 which controls five squares....".

Conversely, on Bh4 has a mobility of four squares whereas on g5 the Bishop has a mobility of eight squares.

Hmmm... thought I was posting this to the errata. Guess I forgot how to use this site .

Somehow I don't think anyone's listening anyway ^_^

Lack of activity here has made me completely forget this site.

PawnCustodian wrote:In the notes after 3.Bh4 the consequences are stated that on h4 the bishop controls 5 squares, whereas on g5 the bishop controls 8 squares.

Actually, this confuses the concept of mobility (defined as all legal moves of a piece) and control (computed by counting attackers and defenders  at the square of each legal move).  

Correctly stated, the comment should read "Bh4 remains unprotected and it controls one square comparing to Bg5 which controls five squares....".

Conversely, on Bh4 has a mobility of four squares whereas on g5 the Bishop has a mobility of eight squares.

'Mobility or Control'...often, concepts are just canards and I would say don't get hung up on any particular word. I prefer the term 'influence' (direct or indirect). They mention 'the point of Bg5' on the previous move and say that it in may ways limits black's development and point out that it DOES have a drawback - b2 is weakened. Note that on h4 it is no longer on its nice original diagonal - lost control of all those squares with nothing in return. Black can therefore gain a tempo (...e5 is an important move and it cannot be taken). Basically, I think they are just point all this out and as it is just the first game of the whole course...want you to start looking at squares...'influenced' by the bishop and Black is able to make use of it and the squares it no longer covers. Yes, the English is bad - the sentence "Does it worth it?" is perhaps the worst.

This reminds me of a nice exercise Matthew Sadler suggest to 'young players' - he means 'inexperienced'. He says to just go thru diagrams in a book and simply note all the squares attacked (by that, I don't think he means say after on Whites second move to count 'h6' and black would just take it) by every piece/pawn on both sides. He notes getting use to quickly noticing all the squares pieces 'controlled' (forget the term he really uses) is invaluable and something that - if you do the exercise a lot - becomes second nature and helps you orient yourself quickly to 'possibilities' in any position. How many times have you seen a weak players simply forget or not even notice important 'connections' between the pieces?