Specific Question on Time Control

40/90, SD/30, +30 second increment

I'm a novice at chess and I've played in only one tournament.  Another tournament is coming up with the time control listed above.  I don't understand the following:

1.  30 second increment.  Is the thirty second increment added to each and every move by each player, in both the 40/90 and SD/30 portions of play? 

2.  40/90.  Each player has 90 minutes to make his first 40 moves.  What happens if one doesn't make 40 moves in that time?  Does he forfeit?   What happens to the player who completed his 40th move in 90 minutes, but the other hasn't?

What happens if both players complete their 40th move well inside 90 minutes?  Do they just keep playing until the 90th minute?

3.  SD/30.  SD means that 30 additional minutes are added and that SD occurs when that time runs out.  But when does SD begin?  Does it begin at the same time for both players?  How is the transition from 40/90 to SD triggered?  Is it triggered at the completion of the 40th move or at the 90th minute of some other way?

Thanks.  The tournament I just finished  was a simple G/120d10.

1. Nomally the increment is from move 1.
2. If one player doesn't complete 40 moves in the first time control, they lose on time. Assuming sufficient material to mate for the player with time. Once 40 moves are done by both players they continue playing until the second time control or the game ends in a draw/checkmate. Unused time is carried over to the next time control.
3. The 30 minutes gets added when the 40 move condition is met. After that move they are in sudden death (the last time control)

Thank your for the courtesy of the reply.

If I understand you, the clock needs to be able to count moves to determine when each player meets, or does not meet, the 90 minute control.  Then, if both players have met the 90 minute control,  the clock triggers the SD/30?

Thus, if Black makes his 40th move at 82 minutes, the clock stops counting the 90 minute control and begins the SD/30?  Or --- since you mentioned unused time being carried over to the next time control -- will the 8 "unused" minutes be added to the SD/30 to create what is actually an SD/38?

Finally, if White makes his 40th move at 80 minutes and Black makes his 40th move at 89 minutes, does White carry over 10 minutes to SD/30 -- and Black carries 1 minute over?

And does this topic explain why a tournament clock has to have the capability to handle all feasible time controls?

Thank you in advance.

Bump.

If not an answer, I would value a reference to a source that could answer my questions.

Hi I just wanna say that the approve move feature on mobile phones is great except if the game has under a minute on the clock it should be automatically disabled.  I also think they should work to make it a feature for desktop because it's an unfair advantage.  

Don’t have time to answer in detail (sorry) but the clock doesn’t need to be able to count moves (although some clocks can).

Bumping after 3h? What are you thinking people do with their lives?

Anyway:

The thirty minutes are (assuming you have a modern digital chess clock) automatically added to your remaining time after the time control. So if one player has 8 minutes left, the other 1 minute, after the control they will have 38 minutes and 31 minutes respectively.

Re "And does this topic explain why a tournament clock has to have the capability to handle all feasible time controls?": I don't get the question.

The clock does keep track of the moves, but it is up to the players to make sure the time control has been met; only score sheets are used to determine that fact.

I have never actually used that type of time control yet, so don't know the exact mechanism individual clock makers use, but the equipment regulations for FIDE, an probably US Chess, spell out what is allowed.

 Let me rephrase -- for clarity.  Since tournaments have all sorts of time controls, I assume that a chess clock that is tournament capable has to be able to handle multiple time controls, distinguish between the nature of the controls (40/90 and SD/30), count moves and display the moves to both players, handle all delays and increments, carry over (add) time appropriately.  In short, after being programmed, a tournament capable clock should track and report time accurately for whatever time controls have been set.

As I recall, some clocks advertise exactly these capabilities.  I'm gonna have to research the clocks because I need to get a new one that will allow me to handle typical tournament time controls.

Thank you for your answer.

Yes, but I'm sure that the time controls used by FIDE or USCF are covered by all of them (provided you get a recent model).

 I don't understand your answer, though I appreciate it.  If a tournament capable time clock is being used, and is correctly programmed, wouldn't it immediately signal that one or both players have not made the required moves in the first time period?  In the case I've presented, what happens when, at 90 minutes, White has made 36 moves and Black has made 35 (accurately recorded on their score sheets)?  Both have not met the time control.  Is the game over?  If it is, who wins?  Is it a draw?

I'm not trying to be pedantic.  Having never played such time controls and having never witnessed them being played, I genuinely don't know what to expect.  I assume that, after Black has made his 40th move before the 90 minute time control, the clock will automatically begin SD.  But, I don't know.

Thank you for the clarification.  It goes a long way toward helping me look for a new clock.

The player who violates the time limit first will lose. You don't wait till move 40, you just claim the win.

Things become clearer.

All clocks provide the ability to manually adjust to any time control. Some include pre-sets, otherwise a manual adjustment can be made, much like setting any wristwatch. Analog clocks obviously can't can't include increment or time delay.

Just think of it as a countdown timer. Certain events will add time, but once it counts to zero, it's over.

The main thing is, the players have to make the claim and the clock move counter is not definitive. Only the completed score sheets can be used to determine if the time control was met or overstepped. 

And clearer.  The dawn begins to break.  O sale el sol.

It sounds like you may be overthinking things somewhat.

Treat the 40/90 as a regular time control.  Only, instead of each player needing to finish the game in 90 minutes, they only need to make 40 moves in that time.  (Note that this means the total time spent on this time control can be as much as 3 hours, or even a little more than that if there is a delay or increment.)  If a player runs out of their 90 minutes without making their 40th move, they (likely) lose the game, or get a draw if the position merits it by the rules.

Once each player has made their 40th move, one of two things should happen.  If the clock automatically tracks moves and is programmed with the full time control, it will add 30 minutes to each side's remaining time.  If the clock does not automatically track moves (or wasn't programmed to do so).  Then, once each player makes their 40th move, you will have to stop the clocks and manually add 30 minutes to the time remaining for each player.  Then, restart the white player's clock and continue the game, aiming to finish the game before you run out of time (30 minutes + time remaining from previous time control).

This is, of course, assuming that the players haven't been forgetting to hit their clocks after every move - this does happen and actually happened to me yesterday at a tournament I was in... my opponent, an older gentleman, forgot to hit his clock a number of times.  I gently reminded him when I could, but there were a couple of times when I made my move within the delay and didn't realize that he had forgotten to hit the clock until I tried to hit the clock on my side and noticed that his time was still going down.  It wasn't a big deal, but it could have caused confusion in a game with multiple time controls.

"The main thing is, the players have to make the claim and the clock move counter is not definitive. Only the completed score sheets can be used to determine if the time control was met or overstepped."

Since I mentioned that it is easy for both players to fail to notice that one or both players forgot to hit the clock after making their move, you can now see the reasoning behind the above quote.  The clocks may only show 38 moves have been made, but if the scoresheets show that 40 moves have been made, then that takes precedence over the move counter on the clock.

Ultimately, 40/90 SD/30 is very nearly the same time control as G/120, for games lasting at least 40 moves.  The biggest difference is that you run the risk of getting into time trouble twice.

Well said, Sir.  Well said, indeed.  You provided a big picture that I could fit the details into.  As to the overthinking, you're correct.  Or I wouldn't be attracted to chess.

Based upon your post, and upon all others who were generous enough to help me understand tournament time controls, I will be sure to get a clock which counts turns and which automatically starts the second time control after the required moves of the first time control are completed.

I also played in a tournament this weekend (G/120 d10) and forgot to hit my clock several times.  Two players pointed it out; two others remained mute.  In one case I ran off about 12 minutes before wondering why my opponent was taking so much time -- and then realizing my clock was still running.

I asked about my experience and was told that your opponent is not obligated to point out your failure to complete your move (by hitting the clock).  And was told that some opponents will gladly take the opportunity to have you run off time.  Live and learn.

Thanks to all of you for your patience and helpfulness in addressing my question, however imperfectly asked.  I appreciate it.