We place clocks on games that go too long. Bringing a clock guarantees that the player can use it for every game. We explain to new players how clocks work before placing them on the game, but any player is welcome and encouraged to ask how they work during the tournament, and parents are encouraged to email us ahead of time if they have questions about clocks. I have received lots of questions from parents, during tournaments, asking me to explain clocks. It is a bit technical and hard to explain.
Overall, clocks aren’t really a big deal, but here is some explanation.
1. Press the button after you move.
2. If you lose on time, you lose the game.
3. Out of 300 tournaments with 40-60 players, I am guessing that I’ve seen about 10 people lose on time. Most of these players were losing "on the board” already. Maybe twice I’ve seen beginners forget to press the clock button, but I encourage young players to remind their opponents to press the clock (this is in the spirit of good sportsmanship but it is technically optional).
The main point: Clocks really aren’t a big deal.
Advanced Tip: You are supposed to press the button with the same hand you used to move the piece. If you move the Rook with your right hand, use your right hand to press the button. This is often known as the “same hand” rule. This rule prevents players from accidentally pressing the clock button before they move, when in fact, they are supposed to press the clock button after they move. It really doesn’t matter much in tournament games, but it’s officially the USCF and International (FIDE) rule and it matters more for the top players.
Very Advanced: When capturing, or castling, you can press the clock with either hand. This is getting really nit-picky I know… but I know of two adults arguing about this a few years ago.
Avoid accidentally cheating: Spectators: When watching another game, never whisper commentary about the clock, never remind players to press the clock, and never mention to the players that someone lost on time. When watching a game, you might secretly be excited by the fact that someone is about to lose on time… but by bringing any attention to the clock, it will effect the game. A spectator that effects the outcome of a game is technically cheating (but we know it usually happens by accident).
Players who make this mistake usually have good intentions, but it leads to what appears to be an overreaction from tournament staff, players, sometimes parents, and the USCF. It gets them kicked out of tournaments, and maybe in trouble with the USCF. Sometimes the player that “benefited” from this advice can get in trouble, even if they didn’t ask for it. USCF resolves these disputes on a case by case basis, but it is not fun! Overall, it’s very important that a spectator never “helps” players or interacts with the players.