I generally play a lot of good games in the morning rounds but after noon, i feel tired and i am not able to concentrate. Is there any routine i should follow to concentrate well? Don't tell me to relax or to sleep well. I do that.
Make sure that you are eating frequently and in small amounts as digesting a large meal can make you feel tired. Banana's are excellent food for this. Taking a brisk walk between some rounds can wake the body back up a bit too.