Help needed with Byo Yomi for a new clock im working on

Hi. First of all some transparency: i am one of 3 designers/developers working on the Tempest Game Clock some but this is not an ad for that, this is a call for some help from the Go community. Originally Tempest was envisioned as a chess clock and it does that very well. But since going on kickstarter, our founders have been hearing from Go players repeatedly to add byo-yomi. Our founders being chess players, asked me (a terrible go player!) to solve for ‘including a beautifully simple version of byo yomi, that prioritizes the most common go time controls, in order to keep it simple.’ there is a huge value placed on simplicity on tempest, so i have a problem. the more i read about go timing methods, the more overwhelmed im getting. and i don’t want to clutter the UI with 100 options. tempest is set so simply compared to dgt, game time, and other clocks we have benchmarked, that it’s almost like go itself : simple rules, beautiful results.

TO SET other time controls on it, users just swipe for MAIN GAME minutes (from 1min up to 2 hours). That’s it! no press and hold and tap tap tap and ‘mode’ this and ‘select’ that. It’s just swipe and play. bam. Now with chess, there are also increments (seconds added per move) but the game ends when main time end. incrments are also set by swipe. so to set blitz chess 5min + 2sec increments, you just swipe min and swipe seconds. the end. (yes, there are super advanced tournament time controls that this doesn’t address, but for 99% of uses the simplification of the UI is so worth it).

So: how to do this with byo yomi for go players? I would like some feedback or even direct engaged help from someone here offline perhaps. Our thought is that if 90% of go timing is covered by one primary method that we could (for now!) dispense with all the corner case. But what would that look like? My thought is: using the same swipe/swipe & play method as the above, we could say: Swipe for main time (as usual), but choose byoyomi (not incrments) by clicking the increment button to make it a [1] (1 extra period) where you then swipe the seconds (from 1 to 60, though this could be increased if you tell me it should) to indicate the byo-yomi time period… want more periods? just click that [1] to make it a [2] or a [3] etc… so you’d see a screen that basically looks like this: 60 [5] 60 and that would mean 60min for main time plus 5 periods of byoyomi of 60seconds each. and that whole ui would fit the tempest model perfectly as a super simple: swipe-swipe-set-it.

what i don’t know is does this capture 90% of casual (or tournament) time control needs without going into advanced corner cases…im working on a story board wireframe of this setting method right now. so i very much appreciate any help i get on this… who knows, i might even part with my tempest sample if someone really helps me stress test this thing!

i hope i have convinced you that this is not an ad, but a call for help! so i am very respectfully pasting a link for anyone that is just wanting to see what i’m talking about for clarity. please don’t consider this spam, or if you do please tell me and i’ll remove the posting or rephrase my ask, but really i am trying to make a better product for go players, nothing more… here is what im refering to… so far byo yomi is just ‘announded’ but not yet developed though:

With respect and thanks in advance for your help.


Your description of byo-yomi sounds fine to me. Probably having a default of 5 periods would work for most cases if you can then just set the main time and the byo yomi time with the swipe swipe thing.
(I must say I don’t fully understand the UI from your description but I’ve not looked at the link contents)

The only think I might say is that I don’t think any tournaments in the UK use byo-yomi any more. It would either be Fischer which you have covered or Canadian but I guess the latter would be very troublesome to implement on a “clean” display!

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Just note that if you want byo-yomi you’ll need to program sound for it.

You could add fourth number for stones to cover Canadian byo-yomi.

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this is great!. @s_alexander how does sound work in its SIMPLEST form? beeps counting down from 10seconds ? is sound always left on like that and does it only happen in the byoyomi periods or do you also need it in the main period? i wasn’t sure if that was ‘standard’ or ‘annoying’… so i appreciate the insight!

i should have mentioned that there is a move counter (aka stone counter) on the main game clockface … it does not (currently) reset when main time hits zero. … should it?

As to canadian byo yomi… if the. clock plays traditional simple byo yomi would you actually use variants like canadian time or stick with simple traditional time? (i am familiar with all kinds of variants in chess that mostly came out of using older mechanical clocks… but now with digital those weird time controls are kind of hangers on)

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@teapoweredrobot thank you! i am thinking (if you are up for it), that i would like to mock up a prototype to show you and if you are willing to look at it your quick critique and feedback could be so helpful to making a great go clock.

i could show you (over zoom?) how the swipe swipe set works currently and how i envision that working for go. (swipe main minutes, pick a number of periods and set byoyomi time). it sounds like canadian timing isn’t just a corner case but common practice? more common than traditional? lemme know if you would like to chat more offline and i’ll show you what we’ve got going here. thank you!


Canadian byoyomi is very common in IRL tournaments because much more convenient for organizing


Mechanical chess clocks can’t be used for byoyomi. Byoyomi traditionally requires a 3rd person to read the seconds out loud (like from a wrist watch, which I have done in the past, like in the 90s).

AFAIK Canadian overtime was invented as an overtime method that doesn’t need a 3rd person and which works with mechanical clocks. But nowadays there are many electronic clocks that support byoyomi, so I think that Canadian overtime is becoming obsolete. But maybe some people still prefer Canadian overtime even with electronic clocks, because they are used to it.

In my opinion, when we are using electronic clocks anyway, I like time increment (like Fischer) better than both byoyomi and Canadian overtime. But time increment is hardly used at all in real life go tournaments (I’ve never encountered it). I suppose the reason is tradition.


It seems that this product integrates with a smartphone, which could provide the sound.

Since sound is required, different voices and language support would be nice.

Maybe an option for Gilbert Gottfried’s voice could be a stretch goal??

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Ing clocks are famous to be. … infamous. To see how they work can be interesting so as to not do the same failures.
They were given by the Ing fundation in large quantities

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If a speaking voice is integrated, note that the traditional way used in East Asia counts upwards to the duration of the byo-yomi period (in particular, it marks e.g. 30, 50, and then counts 1, 2, 3, 4, 5, 6, 7, 8, 9, and says “period passed, X periods left”). On OGS it seems to count down. Of course, with software, it’s easy to just make this a setting (as well as settings for which demarkings to count out loud)

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Since we’ve started using electronic clocks for most face-to-face tournaments in the UK, we’ve generally used Fischer time - and the feedback has been really positive.


This sounds like a product with potential. I have not yet seen the perfect Go clock.

That said, you absolutely need to get it right. If you mess up the byo-yomi feature (for example, not allowing users to set all parameters in the name of simplicity), in my estimation, it will be dead on arrival with respect to Go tournaments.

What you should do:

  • Survey Go tournament announcements of AGA and EGF for popular overtime settings and make them default.
  • Survey western and eastern Go servers for popular overtime settings and make them available.
  • Survey the competition: Ing clocks and the DGT 2010, both are used in European tournaments.
  • At the very least, have “normal”/periodic byo-yomi and Canadian overtime.

The main downside of existing clocks is that they are hard to configure and their interface is confusing.

Comments you didn’t ask for:

If your clock can somehow communicate with the others so that they can all be set up at once, that would be a smash hit.

There have been use cases for starting the clock from an asymmetric configuration, e.g. when the referee needs to give extra time after an interruption or as penalty.

I feel that modern UX design too often conflates ease of use with lack of features (“dumbing down”). This does not have to be the case! Exploit the potential advantages of well-designed UX without sacrificing power.

This was all very abstract, so let me conclude with something more concrete.

Here are some examples for the parameters to be set on each side.

  • periodic byo-yomi: 1:30:00 + 3x10 (90 minutes main time, overtime 3 periods of 10 seconds each)
  • Canadian byo-yomi: 1:00:00 + 15/5 (60 minutes main time, overtime 15 stones in 5 minutes)
  • progressive byo-yomi: 1:00:00 + 10(+5)/5 (60 minutes main time, overtime 10 stones in 5 minutes increasing by 5 stones every period)

If it’s a product that needs a phone in order to work, it might not be really usable for tournaments anyway. Either the organisers have a bunch of smartphones to put on every board, or the players need to use their own phones, which they may or may not want (or be able) to do.

Are the codes to sync the mechanical clock and the app reusable? Is the app just free to download anyway?


Simply enter the code on the bottom of your Tempest™ base to pair it with our software. The clock base and app are designed to work seamlessly together!

I guess that answers that. Still the issue if you’re relying on each pair of players having one smartphone, and then of two people who don’t play each other they need to borrow a phone.


In simplest form clock beeps but when exactly is a bit up to implementation.

Generally you don’t need any beeps in main time. In byo-yomi you need some beeps. (And probably you might want different way of beeping in last period for the player to know they’re about to time out)

Something like beeps at 10s-5s-2s long beep at losing period.

I’m not really an over the board player. Better steal the implementation from real clocks.

Sorry for not getting back to you. I’m not really interested enough in the clock itself I’m afraid as I’ll never need to use one (if i do it’ll be in a tourney where they will be provided).

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