Chess without tactics might as well be checkers. Mostly kidding of course, but that's all chess is, is tactics.

Chess is quite a bit strategy. In fact, normally almost all of the opening is strategy. Apart from the exchanges and mate, most of the other moves are strategical and not tactical. You could be great at tactics, but not so good at strategy and GM's would destroy you.

GM's would destroy you regardless, but I do see your point.

Chigorin said:"mastery of the art of the art of combination, the ability in any situation to find the most effective move to carry through your chosen plan as quickly as possible - this is higher than any principles, or more correctly, there is only one principle in chess, and this is it's definition".

Petrosian suggested that tactics is hammer and chisel, while strategy is a block of marble.

The idea that tactics is a mistake is ludicrous. Tactics is a reality check - brings you down to earth with a thud!

I think the OP was pokin fun at the idea that, ordinarily, in order for tactics to occur, someone has to make a mistake. With perfect play, a game is a draw through all of it's phases, with mostly straight up trades, though they could still be considered tactics. They aren't the most desirable type of tactics though.

I think some people get annoyed by the idea that, others give themselves too much credit for great play, when in reality, their opponent's mistakes are what made for the possibility in the first place. I think the OP was also looking to stir this bunch in particular that, are in a hurry to pat themselves on the back for their opponent's mishaps.

how many moves deep is required to play perfect chess ?

If there are only forced moves it's not your opponent's mistake

Then you are saying that there is a line that is unrefutable and thus perfect play by both sides isn't a draw...

...From my experience and understanding, there is always a counter to equalize, if there are no mistakes...

Show me one tactic that gives more than a pawn advantage without a mistake....

tell me the value of infinity.

it's priceless....

Nine!

bigpoison got it!! a long string of nines. that's just a single 9 with a dot on top.