A few years ago we decided to run our events with only a single time control (I.e G/120). There were several reasons for doing so, but others promoted their own reason for continuing with using multiple time controls (I.e. 40/90; SD/30).
In the March issue of Chess Life, GM Andy Soltis in his “Chess to Enjoy” column, presents the major reason why a single time control would be fairer. He points out that having the first move in the 2nd (or last) time control gives white a major advantage.
This is far from obvious to me.
As usual, Soltis exaggerates for the purpose of writing an entertaining article. He gives examples in which White already has a winning advantage at the time control. In practice, it is just as common that that there is no decisive advantage at the first time control and that Black (even if under great pressure), with more time to think in a 2nd control finds a saving defense. I think this perceived time control advantage to White is mostly an illusion.
I have played G/120 and my observation has been that the overall quality of play is distinctly lower than with two time controls. A second time control is a good thing, because it allows both players to raise the level of play again after any distortions caused by time pressure around move 40.
– Hal Terrie
Soltis presents some compelling examples and statistics.
No he doesn’t.
– Hal Terrie
It seems plausible to me, in certain kinds of positions.
If both players are in extreme time trouble in a complicated position, many of the moves are likely to be blunders. As an extreme example, let’s say all moves 31 through 40, by both players, are blunders, to the extent that each of these moves converts a won position into a lost position.
This means that, after each white move, black is winning, and vice versa. The players are taking turns handing the game to each other on a silver platter.
When time pressure finally ends, it will be white’s 41st move, and white will have a winning position because black just blundered (again) on his 40th move. Now, with plenty of time, white will be able to navigate the complications and win his won position, even against best play by black.
Bill Smythe
As a director, I prefer a single time control. Events with single time controls are easier to run, IMO.
As a player…the sad and sorry truth is that I play far too fast for it to matter to me, either way. 
But I don’t mind having more than one time control in a game.
Very true. For one thing, all the arguments about when to add the extra time, whether to turn on the move counter, whether there has been a time forfeit, etc, are avoided.
I firmly believe that, had technology been more advanced so that the increment concept had been available early on, multiple time controls would never have been invented. Multiple controls are simply a poor man’s way to approximate increment.
Bill Smythe
I just scratched my head over this one. If any “advantage” materializes at the start of the second time control, it’s to the person who was not in time trouble.
CL never ceases to amaze.
Nicely stated.
The only time the argument that having the first move of the new control would be valid is if there was a mutual time scramble at the end of the previous one. I think the claim of a single control being fairer is exaggerated if it exists at all.
As for 1 control vs. 2 consider this: G/180 vs. 40/2, SD/1. The biggest difference would be that there will be a lot more games going into the fifth and sixth hours and then games on average game will take more time. The final time scramble of a 1 time control event will have more moves and pieces involved than the second of 2.
I’ve heard a few players say that having the two time controls helps them with pacing their play. They end up spending much less time on obvious moves or overcalculating tactics early on because they want the extra time when the critical positions arise around moves 25-35. I can see where this would simplify the thought process early on in a game and create a higher quality game throughout.
If black is the one defending all game, then black will tend to find himself more likely to be extremely short of time. And if he is low on time, then black is more likely to make a fatal blunder, unable to find the one move that holds the thread. Of course, these blunders often happen on the last move or two of time control.
Therefore the person moves first after time control has a (small) statistical advantage. It is, however, a consequence of moving first at the start.
IN FACT, the person who MOVES FIRST at the beginning of ANY TIME CONTROL has an advantage, because that person is always UP A TEMPO. Black is hurt just as much in a single time control. I should add that the theoretical advantage of the first move is felt much less at lower ratings.
To mix things up, we would have to make the time control 40/2 for white and 39/2 for black. Now that would be a paradoxical way to compensate black for white’s inherent advantage on the first move. Only if black survives all the way to move 40!
Michael Aigner
As a player, I’m fine with one time control, if it’s two hours or less.
I would, however, hate G/180, because of that occasional opponent who refuses to resign a dead lost position, and who, on top of that, takes forever on each move.
Bill Smythe
G90/ 30 sec inc, is plenty of time, anyhow.
Rob Jones
My preference would be to standardize regular-rated events on one of four time controls: G/30+30i, G/60+30i, G/90+30i or G/120+30i. Switch to FIDE scorekeeping rules, too. 
As a TD I prefer 2 time controls. Keeps the games moving along.
30/60; G/60 is pretty close to ideal.
Having supervised a lot of master-level events with 30 second increments, and read descriptions here of the personal distress of people caught in living on the increment for long periods of time, I am wondering if longer increments might be worth trying.
For example, 40 minutes plus 60 seconds increment, or 60 minutes plus 90 seconds increment.
Possible advantages include being able to build up enough time in very few moves to get a bathroom break late in the game; being able to build up enough time to take a long think now and then, even in endgames; and making it more likely that play can remain at a higher level later in games.
I wonder why GMs were howling mad when FIDE listened to Mr. Jones a few years back?
Interesting theory. I am a believer in Increment.
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Having one long or “fat” time control introduces unwanted luck into chess (which inclusion of Increment can only reduce not eliminate).
I have played chess games that ended quickly and consumed very little time. I have had other games that would be described as long marathons. In neither case did I have any clue which game might run short or long — and therein lies the problem.
There cannot be enough information early in a chess game to enable players to budget their time in a fully rational way. So players guess, either deliberately or implicitly. The need to guess implies luck.
By comparison, this kind of time guesswork is almost nonexistent in analog sports like basketball, soccer, or tennis.
To greatly reduce the time-related luck in chess, more time controls are needed than just one. A scheme that uses several exceedingly short or “thin” time controls reduces luck the most.
Or how about one time control of 15 minutes / Game + 150 seconds increment per move. In effect this would be like a whole new time control per move.
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