In Boxing, the part of the heavyweight fights known as "Ali's Alley" were rounds 11 to 15. That was the time when Muhammad Ali would find his second wind and step up the pace.
In chess, moves 25 to 40 present contestants with situations that will separate masters. Just as the position is most difficult, the clock is ticking down. Just as the battle enters its third, and maybe fourth hour, the tension rises to its peak. Error Alley can affect any player at any level. Error Alley need not feature a sharp position to wield its terror. Here is an example from the last round of the National Open between Kayden Troff and Gregg Small.
I have added my own annotations over those provided by Kayden Troff. This game doesn't have much theoretical or strategic value, EXCEPT that it is a great example of what can happen in Error Alley. Black's game ending error was committed on move 32.