Klaxon
An online quizbowl buzzing system.
Klaxon is a buzzer for quizbowl, built for the particular problem of playing the game when the players are not in the same room.
In a physical match the buzzer is an honest instrument. Two people sit at a table, each rests a thumb on a button, and the device reports, without opinion, which thumb moved first. Move the match onto the internet and that honesty quietly disappears. A buzz no longer travels a few inches of wire; it travels from a laptop in one city to a server in another and back, and the trip does not take the same amount of time for everyone. A player on a fast home connection sits closer, in the only sense the network cares about, than a player on a phone in a school hallway. Left alone, an online buzzer rewards the connection rather than the reflex, and it does so invisibly, which is the worse of the two.
Klaxon's work is to give the reflex back its advantage. When you press the button, your device notes the precise moment of the press and sends that reading along with the buzz itself. A single server, which no player can reach or argue with, serves as the referee for the room. It does not settle the order by which message happens to arrive first, since that would be a contest of bandwidth. It settles it by when each player actually pressed.
To do that it has to know how long each buzz spent in transit, so it measures the distance, continuously and on its own, for every player in the room. When a buzz arrives, the server subtracts that travel time and recovers the instant the button was really pushed. A player across the country and a player across the street, pressing at the same moment, are recorded as tied. Distance stops mattering, and reaction time is all that is left.
A short, deliberate pause is built into this. The moment anyone buzzes the reading stops for everyone, but the system waits a fraction of a second before it commits to an order, long enough for any buzzes already in flight to land. Only then does it rank them by their true press times, so that two players who lunge at the same instant are judged together rather than by the accident of whose signal finished first.
Because the system credits a buzz to the moment you claim you pressed, it is careful with that trust. The server is the only authority: your device may request a buzz, but it cannot award itself the point, alter a score, or take control of the buzzer, because none of those things live anywhere a player can reach. The server measures each connection for itself rather than believing whatever a browser reports, so no one can pose as more distant in order to be handed extra credit. There is a firm limit on how far back a press can be placed; a buzz can be rewound only as far as the player's real connection allows, and a claim to have pressed impossibly early is discarded rather than rewarded. Timing that looks engineered rather than human is noted.
A word of realism about the larger setup. Most online tournaments run over a video call, usually Zoom, and a video call carries a delay of its own that Klaxon has no way to remove. The question reaches each room through that call, and Zoom does not deliver sound to everyone at the same instant; one room may hear the last word of a clue a beat before another does. Klaxon governs the buzzer, not the broadcast. It can only be fair from the moment the audio actually reaches you. It corrects the part of the chain it controls and stays honest about the part it does not.
That is most of the design. Klaxon removes the unfairness the network introduces and then declines to add any of its own. It cannot make you quicker, and it is not trying to. Once the connection has been taken out of the argument, what remains is the thing the game was always about.
Created by Michael Bentley.