For the past 3 years that I have been doing programming contests, I've noticed the trend that I very rarely solve problems in the last 1/6 to 1/5 of the given time in any competition (e.g. last 20 minutes of a CF round or last hour of an ACM event).
Sometimes this lack of efficacy is due to not knowing a niche technique, or running into a genuinely hard problem. However, more often than not, I open the editorial and groan at not seeing a solution that I was millimeters away from on pen and paper. I have never went into the home stretch thinking I would not solve anything (so I don't believe its my mental at fault), but I would like to figure out if there is a way in addition to straight up practice that more experienced coders use to make the most of every minute of competition.
Hopefully those people can share their insights for both myself and the CF community. :)