Hourglass Timing is the time system where
- one gets an amount of time,
- and time used for each move is deducted
- and added to the opponent's time.
|===|-------| time before
|--| time for one move
|======|----| time after
Both players start with the same time on their clock.
Despite being simple, it invites unreasonable fast play to force the opponent to play as fast.
Essentially, it emulates keeping time by using a single hourglass, which is flipped as each move is played. One bulb represents the white player's time, and the other bulb contains the black player's time.
In practice, another problem crops up if you were to attempt to use an actual hourglass, namely the difficulty of setting the initial time. It is difficult to tell exactly where the halfway point is on an hourglass, and the setup requires you to 'run' the hourglass halfway through before starting the game.
HarryFearnley When wanting to play lightning games, I have frequently used an ordinary egg-timer "hourglass", and found it simple to use. To get fair initial times, simply use cut-and-choose: one player attempts to put equal amounts of sand in each bulb. Then, the other player chooses which end is theirs. Sharing only 5 minutes of maximum time-difference in this way means that the faster player can put significant pressure on the slower -- something that I like. Of course, using the same egg-timer, two players of a more gentle disposition could play a whole game at a very slow pace of almost 5-minutes-a-move.
By the way, there is no need for players to start with the same time. It is possible to time-handicap one player just as one can with an ordinary clock. However, the handicapping behaves very differently -- 4 minutes for one, and 1 minute for the other is not equivalent to the first player having 4 times as much time as the second.
10 minutes each.
# Time Used -------------------------- 1 10:00 10:00 1:30 2 8:30 11:30 1:40 3 10:10 9:50 2:00 4 8:10 11:50 0:20 5 8:30 11:30 5:00 6 3:30 16:30 0:30 7 4:00 16:00 4:00 8 0:00 20:00 lost