garyt1957 I assume they just take the chance that they're going to know the answer and buzz in before the clue is anywhere near finished
I can guarantee no one's done that since 1985.
The current buzzer system is disabled until the clue has finished being read, and a light comes on that the players can see. If a player buzzes in before the light comes on, they are locked out from buzzing for 0.2 seconds. Most player's know not to wait for the light, however, but to try and time when the Jeopardy staffer will be pressing the button to turn on the light - since the human physiological reflex delay (see light - press button) is also about .2 seconds. Matt's timing, after this many games, is probably going to be better than most other contestants - even though they are provided with practice rounds to get the hang of it.