I've decided to start doing tons of tactics problems.  After about 30 minutes of them, I thought, is there a point at which you should rest, because you are too tired and start blowing them more than you get them?  My answer was yes, there's got to be that point. 

    How many minutes do you practice tactics till you take a break?    I kept going for an hour, then took a break.

   Now I'm thinking dumb question - just stop when you start missing a bunch in a row, whatever that time is. 

   So, what's the longest you've gone before you took a break? 

I've always been amazed that people can get through 30+ minutes of tactics daily. They always bore the hell out of me and I've never been convinced by the argument that novices need such intensive tactical training.

At the point where you do not even calculate all the lines through, it's useless to keep doing tactics. Of course, it's harder to feel that time when you are tired and go into the mode 'as fast as I can, looking for every dubious sacrifice'.

Depending on the difficulty, I cannot stand more than 15 min on a really though one (or a bunch of tough ones), but when it's 'training for the blitz - less than 30 s on each' I might be able to hold >30 min. Never tried it though.

After posting this, I went back and did 30 more minutes.  Then I got tired of them, plus my score was starting to fall.  So that's a good question, is an hour of tactics too much to do anyway? as Ireland above suggested?  (I'm doing them on the other site, BTW, where you are not penalized for taking 30 seconds or more.)

  ON this site today, my tactics rating dropped 120 points after doing 30 mins of them.  Don't know if they were getting THAT much harder or I was already tired.   I think tactics here is strictly for Blitz training - don't think I'll play them anymore here.  I'd rather get the answer right, even if it takes me longer. 

    Someone just said, in answer to my question how to get better, "do tactics, tactics, tactics."  Course I'm reading a book by Stillman and another's on the way for middle game and end game. 

I'm a non-paying member (freeloader), so with my 3 free problems per day I'll never reach the point of diminishing returns.

Awesome.  One less thing to worry about.

Amy