fritz interface questions

I have three questions about the fritz interface...

1. What does the green button do as indicated by the green arrow?

2. I know what depth is, but what does the backslash and the 2nd number indicate, as shown by the red arrow?

3. What is the information in the box shown by the blue arrow?

Thanks a bunch!

Wow, that really came out small...in the red arrow box it says "Depth=36/68". In the blue arrow box, it says "22...Kh6 (12/27)", however, the top two plys say "22...Nf4" and "22...Ne5".

Yes, thie image is small, but you can put your mouse over the image and right-click and select VIEW IMAGE and you can see it at its original size.

I think the green button simply means Houdini is calculating.  When it's red it's not calculating.  (I'll have to double check this later.  I'm on my way to work right now...)

The 68 indicates the number of plies ahead Houdini can look ahead in that position.

The denominator 27 is the total number of valid moves in that position.  The 12 indicates this is the 12th move Houdini is evaluating, of these 27.

These two pages might help:

http://uscfsales.wordpress.com/2011/07/08/understanding-chess-engine-evaluations/

http://www.chesscentral.com/Chess_Engine_Displays_a/204.htm

http://www.chessbase.com/workshop2.asp?id=1699

The "Depth" box shows how far ahead Fritz has searched. The first number (before the slash) indicates how far ahead Fritz has looked in a "brute force" search (trying to see every move, and every response, and every response to those responses, etc.). This figure is given in plies. A ply is a half-move (i.e. one move by one player), which is different from what most players normally think of when someone says "x number of moves". For example if someone says "My game lasted forty-five moves", he's talking about 45 moves for each player -- this would actually be ninety plies when expressed in half-moves. So with a twelve ply brute force search (as shown in the display), Fritzis actually looking six moves ahead in the game.

The number after the slash refers to a selective search -- variations resulting from forcing moves like captures and checks. Normally this number is much higher than the brute force value before the slash. I snapped the above graphic just as Fritz was starting its twelfth ply, so the values were the same at that time.