High Level Tactics

You will see layers of tactics, with red herrings that look like good moves, but actually lead to subtle disasters.

Whilst the number of tactical themes may be finite, it's not a small number. Plus, you get combinations of tactical themes such as a removal of the guard exploiting a pin forcing a move that leads to another tatcical position.

As the levels of difficulty increase, you need to be increasingly accurate - the problems will be higher rated as many fail them. One of the main reasons for people failing the problems is that a move that looks winning has a cunning defence and, whilst the idea is correct, only 1 of several moves both continues the threat and defends against the refutation (a perpetual check for the defending side etc).

Then you have to take into account that these accurate moves need to be found not just on move 1 but sometimes for 5 or 6 consecutive moves against slippery defences. "Quiet moves" - ones that don't immediately check or capture but perhaps prevent a defence are often missed and these will cause the problems to be rated higher too.

It sounds like you've made excellent progress with your tactics training already - keep going!

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Hi Julius, Alchemos explained it well imo.

Have you watched this series by IM Danny Rensch?
http://www.chess.com/video/player/patterns-everyone-must-know-mating-nets---1

if not, I can highly recommend it.

On Chesstempo I have reached over 1800 so I don't get any more benefit out of it anymore.  I like to burn basic patterns into my head whereas at that level it's more about training long and involved calculations.  Learn basic patterns first (especially at your level) as they're the building blocks of more complex tactics.

Also, Learn basic strategy such as learning the imbalances and ascertaining which are most important, as those are the basic units you need to comprise a plan.  Tactics are great, but when there are no tactics you need to build up your position. 

I was at 1485 already, inspired by GM Jack Daniels. Currently around 2500-3000. The secret with TT is that normally the 1st move you see is the wrong one. Unless it is a sure move. Sometimes I make the right move in 15 seconds and average time is 4 minutes and sometimes I can not see the right move at all and average time is 45 seconds. Most important : Use your instinct !

it kinda looks like this:

http://www.chess.com/tactics/?id=163073

also there are some problems where you need to realize that you should be aiming for a draw - either by stalemate or perpetual, but it's not always so obvious cause your opponent is sometimes only up by a pawn like the following.

http://www.chess.com/tactics/?id=22008

The "big difference" to me is between tactics that have a forced main line (the solution) and nearly no sidelines to calculate, and tactics that contain non-forcing moves, but every try by the opponent fails for one reason or another.

The second type are a lot of fun to solve.  I don't get much pleasure from the first type even if it's a very difficult series of moves to find and I can't solve it... I see the solution and think "that's boring" heh.

@dacster13
That first tactic is ridiculously simple... a 2500 rating?  There must be tricky 2nd best moves that are throwing people off.  This is not an advanced tactic in any way IMO.

@wafflemaster
It's probably the sequence of moves, people probably play the b4 move immediately not seeing that black can play Bxh6 which saves the knights. A lot of the tactics at 2500 make you think twice because some look simple but when you make the move it's incorrect, and sometimes it's really just as simple as it looks. Usually there is a hidden trick or defense by your opponent somewhere in the sequence, so it requires the solver to actually see the differences in variations although the moves look like they are leading to the same thing.

I guess that's the difference between a difficult timed puzzle and a difficult tactic?

Not that drilling these basic patterns is bad, it's useful if you can see them quickly, but there are also tactical puzzles that are hard to solve given 10 minutes.  And no not those ridiculous ones with 15 rooks on the board, puzzles from real games.

The solution wont be a basic theme like attacking a pinned piece, removing the defender, a fork.  Like AdamRinkleff said it will have layers and the problem becomes finding the best defense for the opponent not moves for yourself.  You can usually quickly spot likely tries, but they should all fail for one reason or another and only the solution works.

Here are some themed examples followed by a non-themed tactic:

Pin theme:

Removing the defender:

Fork:

Non-themed:

This is the highest rated tactic: http://www.chess.com/tactics/?id=38541
An interesting rook sacrifice which you would have to work out all the reasons Black cannot decline it, despite having a few places to move his queen, and that when he accepts it you can force the win of his queen 4 moves later.

You can view and attempt any problem you like: http://www.chess.com/tactics/problems?sortby=rating_hard