Rabirashmi Roy
Triple Block Time Control
ICCF's Triple Block System can be a source of confusion for some players. The rules and intricacies can be daunting. In this article, Rabirashmi Roy explains the Triple Block System (TriBl). If you are playing in an ICCF Tournament in which Triple Block time system applies, you should read this article very carefully.

Editorial Note:

The first thing to do is to read the TriBl rules from the ICCF site. The main ICCF Rules document (Main-menu → ICCF Rules (2021) → ICCF Rules) now covers both the STANDARD and TRIPLE BLOCK systems in one document. In this document, in Appendix 3, The Triple Block Time Control system is explained in detail.

If you want to read the older document, you can still find it by navigating from the main menu → ICCF Rules (2021) → Older Rules, then scroll down to Triple Block System Documents and click 'Explanation of how it works'. Here is a direct link to the old document.


Triple block time control was introduced by ICCF in 2017. As the name suggests, the system consists of three blocks.

Block 1: The clock

At the beginning of the game, the clock is set to 50 days. The clock can never show more than 50 days.

A player loses when his clock reaches zero.

Block 2: The increment

Those of you who are or have been in service, know that you earn increments after rendering a certain period of service in your job. Say for example, you earn an increment after rendering service of one year. In this system, you earn an increment for making a move. The amount of increment varies from tournament to tournament and is decided by the tournament organisers.

Suppose you are playing a tournament in which the increment is 3 days. You make a move on the very first day and earn an increment of 3 days. Since this is the first day of the tournament, your clock is showing 50 days. Now your clock can never show more than 50 days. So where will your increment of three days be added? Herein comes the necessity of a bank which I shall discuss later.

Guaranteed time:

Guaranteed time is not a block of this system, but is a special feature of increment.

You know that you earn an increment for making a move. But this does not go on for indefinite number of moves. You earn increments only for the first fifty moves of a game.

From the fifty first moves of a game, when you no longer earn increments, it is obvious that both your clock and bank will keep running down. It has been observed by ICCF that certain players, who are in a loosing or disadvantageous position after fifty moves, try to take advantage of this loophole by continuing play and try to run their opponents out of time.

Hence this guaranteed time ensures players will have certain number of days as reflection time for making a move after the 50th move. At present, guaranteed time set by ICCF is 3 days per move.

Guaranteed time is not a mandatory feature. Tournament organisers will decide whether or not to allow guaranteed time.

Basically, a guaranteed time of three days means from the 51st move onward, your clock will not run for three days from the time point of your opponent's move. If you make your move within this reflection time of three days, your bank balance and clock balance will remain intact. If you take more than three days, your balance will reduce.

Block 3: The bank

The bank is where you store your time earned from increments.

At the beginning of the tournament, your bank is given an initial balance by the organisers.

Suppose you are playing a tournament with 75 days initial bank and 3 days increment for the first 50 moves. At the beginning of the tournament, you will have 50 days in your clock and 75 days in your bank.

If you make your first move on the first day, your clock will show 50 days and your bank will show 78 days (75+3). If your first move is on the second day of the tournament, your clock is reduced to 49 days and you bank, as earlier, is 78 days. In this case, the server will transfer one day from your bank to your clock making it 50. Thereby, after your first move, your clock will show 50 days and your bank balance will be 77 days.

Thus, the clock is automatically replenished from the bank as long as you have balance in your bank.

I shall explain this process with an analogy:
Suppose you have ₹ 500 in your bank. You have ₹ 50 in your pocket and that is the maximum amount you can keep in your pocket. Your pocket gets replenished from your bank to a limit of ₹ 50 every time you spend money from your pocket, as long as there is balance in your bank.

You spend ₹ 10 from your pocket and balance is reduced to ₹ 40. You earn ₹ 20. So now you have ₹ 40+20 = 60 in your hand. But you can keep a maximum of ₹ 50. So, ₹ 10 goes to your bank making your bank balance ₹ 510.

Here the amount you spent is equivalent to the time you spend for making moves. The amount you earned is the time you earn from increments.

Advantages of triple block system:


Additional Notes: (A.Chatterjee)

Criticism and comments by some AICCF Members:

TriBl appears to be a needless complication. It requires players to read all the rules very carefully and get used it. It requires players to be always conscious of the days in the bank. The main purpose of TriBl was to ensure that games finish before a definite date. This was achieved by introducing "sudden death" - and really there is no other way than sudden death to ensure the finish of games by a definite date. Tournament Organisers also have a Guaranteed Time (Sudden Death Protection) option - but in this case the end date of a tournament cannot be predicted with certainty - which of course means that the main purpose of introducing a complicated system is lost. Moreover, players participating in several events with different TriBl options have the likelihood of getting confused.

Both increment (Fischer Clock) and sudden death are part of OTB and online chess. Players are already familiar with these concepts. But to avoid the concept of leave, ICCF has introduced a bank. This is an unfamiliar concept in the present context. Instead what could have been done was to limit leave to 20 days per player for the entire tournament. The tournament end date could be projected by adding 40 days assuming that both players utilize all their leave and without overlap.

ICCF has another purpose in introducing the concept of a bank. In TriBl, to avoid loss, players need to either move or transfer time from the bank within 50 consecutive days. This effectively replaces the silence rule in standard time keeping, which requires players to either move or inform the TD within 40 days.

Many AICCF players feel they would be happier with the introduction of increment and sudden death, but with the retention of (limited) leave and standard silence rules. In fact, one should have a strict 40 day silence rule, with no possibility of taking more time after informing the TD.

TriBl is here to stay. As more and more events move to TrBl, we will just have to accept it and get used to it.