Ahhhh.... Chess Clocks
Sometimes a chess game can take a while, sometimes one player is pretty quick on their moves while the other leisurely takes their time, this is where chess clocks come in handy. At their most basic functionality, chess clocks serve as countdown timers. Each player has a button that starts the others timer and pauses their own, if a checkmate (or draw) isn't made before time runs out, the clock decides the winner.
Sounds simple enough, and it is, but then chess players started adding features to the chess clock that added a bit more complexity to the timer. Increments and delays (there's really not a whole lot more you can do with a timer than add and subtract time).
It's actually not that complicated at all, the main thing you need to know about are Increments and time delays.
Delay - At the beginning of every move a specific amount of time (delay) needs to pass before the clock starts counting down.
Increment - A specific amount of time is added to a players clock, this can either accumulate (Fischer Clock) where a player can end up with more time than they started with or it can be capped off (Bronstein Clock... sometimes referred to as Bronstein Delay) where players are not able to accumulate more time than what they started with.
There's a bunch of clocks available but three manufacturers pop out to the fore-front of this niche.
ZMart Fun (ZMF) These are sleek minimalistic style clocks with two models currently available. The ZMF-II is their most popular model and offers a unique colored LCD display. They offer several different game timing settings and can preform increment, delay and move counting (not Bronstein delay though). They come in hard plastic, take 4 "C" batteries which they claim provides power for over 1600 hours.
Visual Tech Currently offers one clock the VTek 300, it is a large sharp LCD display and a metal housing offered in various colors. This clock is feature rich, you can access all the settings through its menu driven display. It includes all the time increment and delay features mentioned above (including Bronstein delay) which support both USCF and FIDE standards.
DGT King of the hill, DGT is the leading chess clock manufacturer, they also produce electronic chess sets that are used at all of the major chess events. They offer several clocks from basic ones for beginners and students, to the ones used in grandmaster tournaments.
Lets check out some clock...
The DGT1001 is a basic chess clock made from the premiere chess technology company DGT. It's intended to be simple to use and preforms as a count-down and count-up timer. It's a good choice for an entry level clock, or for chess classes/clubs.
The ZMF-II has a clean minimalistic and functional design. The three buttons allow you to scroll through the menu driven interface to select a variety of modes and functions. The colorful bright ½” bright LED display is great, it also uses 4 “C” batteries which are suppose to give the clock over 1600 hours of life, much more than other clocks. They come in a variety of colors and can have a scrabble mode and byo-yomi mode (used in the game go).
The ZMF-II is clean and it comes in a variety of bright LED colors
The "Official FIDE Chess Clock" this is a pro chess clock, it has all the chess time derivations and includes Byo-yomi settings for Go, Baduk as well as settings for Scrabble. It also has 36 user presets, and a large paddle for using the clock.
This is the chess clock you'd see Magnus Carlsen and Bill Gates use if they were to ever square off
DGT North American
This is a stripped down version of the DGT2010, it was designed to cater towards common North American tournament play. It does not feature the Bronstein delay, or Byo-Yomi, or count-up modes for Go and Scrabble. The delay mode does not show the total time a player has, instead it shows a countdown before the clock starts.
The North American
The DGT3000 is the most advanced clock from DGT. It's can do all the different timing modes, plus shows a move count and periods on the display. In addition to this it hooks up to DGT's series of electronic boards. It's the clock you see at high level tournament matches that broadcasts the players moves off electronic boards. It's awesome.
So, the DGT Pi is not really a chess clock, it's more of a chess computer with a DGT 3000. But it's so cool we had to mention it. It has 8 powerful built in chess engines, which allow this unit to serve as a great chess coach and sparing partner. You can use it for training and for analyzing games.