Draw by repetition

Question. Ranks one and eight only have a king and both rooks, none of which has been moved. Both can legally castle long or short.

65. .... b4  (this is a new, sole, first position, and no previous positions will ever be relevant to this or future positions.) (The same if a piece, was captured by another piece.)

66. 0-0  Was this a new position or not? Black can still castle and has the opportunity, but white does not. If black always has the opportunity to legally castle with at least one rook, then there is no possibility for repetition to occur. (that is until he castles, temporarily is unable to castle, or loses the right to castle)  ???

66 0-0 means that no position prior to that move can be repeated after that move.  When a TD (arbiter) looks at a scoresheet anything before a capture or pawn move or castling can be ignored when doing a quick scan for evidence of three-fold repetition.

@jetoba 

Okay that makes perfect sense. However after castling can a 3 fold repetition ever take place when black on each and every next turn be able to castle as his next move?

After castling you have a new starting point but a position that subsequently occurs can be reached two more times.  If the opponent also castles then you have a new starting point but there can still be three-fold repetitions (of a position that occurred after the castling).

Not too long ago I had an endgame position where I was down in material but had unstoppable checks that resulted in three-fold repetition.

@jetoba 

 White has just castled.  Black can castle but instead moves a bishop. White moves a knight. Both sides continue to move only those pieces. Is it a draw when they reach the same position  3 times, created when white castled? (With black to move )

From the time the White knight moves, the White king has already lost the castling rights. If one exact position appears, and Black's castling rights remain unchanged, then two more occurrences of the same position will result in an automatic draw on this site.

So once someone castles. the rules pertaining to same legal right  to castle for both sides, is nullified and not longer count. Correct?

@eric0022 and at @ThrillerFan

I am straight now thanks to ThrillerFans spectacular example. Post 11 in the following thread. https://www.chess.com/forum/view/game-analysis/reason-for-draw Not quite sure how I got twisted around, but set now. Thanks for everyone's responses. 

Yes, since the "list of possible legal moves" would have changed.

No.  It is only nullified for the side that castled.  Eligibility to castle still applied to the other side up until they also castle (or move the king or nullified on one side if they move the rook).

I like to think of a position being an image or photo so the following will reflect this.

Castling is a new first, and sole position, which nullifies all previous moves. Even if the king and rook return to their original squares, and black moves creating the same image, it is not the same, even though it is whites move. This is because previously white could castle, and now is unable.

After castling, each and every move made after is added to this, unless a pawn is moved, a capture is made, the potential for en passant to be completed arises, if the other side castles, if a king which is able to castle moves, or rook which is able to castle with moves (even if either moves back to it's original square and the move order and image is the same) , which all resets the board, becomes the new first and sole position, to which future positions are added to.

It is interesting that the FIDE laws are not all that clear about this. A position could be looked at in 2 ways: (a) the photo revealing the place of all the units on the board at some point in time (b) the same as "(a) " but plus all the invisible rights and potentials of the units.

In the context of math or computer engineering one would refer to the 2nd definition as the state of the system. Which is way more relevant to its operation than (for instance) what the system displays in its user interface.

Anyway you must be careful when anyone refers to the 3rd occurrence of a position. What do they really mean? (a) or (b) ?

Thanks for later clarifying.  I initially thought you were saying castling rights were irrelevant for future occurrences.  With your clarification I now realize you were saying that the castling change for one player meant that all past moves to that point could be ignored for future claims (which is correct).

Sorry about the misunderstanding of what you were saying.

@jetoba  You were pretty close. That what I thought eric was saying. Soon after  searched and found thrillers tutorial and got it figured out, I responded to your post to help make sure I did get everything right. Thank you very much for your time and help.

@Arisktotle  Little is clear, and especially with this the wording is ambiguous.

I hadn't imagined that a game of chess could end in a draw by repeating without making any successive moves. Thanks for the tip. 

This sounds great