Calculation Practice for the Weekend
In Wisconsin when I was growing up we used to have limitless time controls with two hours for the first 40 moves and one hour for each remaining set of 20 moves in perpetuity. Since they tried to fit in at least two games per day this meant that we sometimes had to start one round before finishing the previous one. After 62 moves and the only adjournment of my chess career, we reached a critical position. White has a dominanant material advantage and three legal moves. My opponent only found the second best option and I made a lucky escape.
Enjoy and feel free to leave answers in the comments.