Daily Archives: 19 March 2023

Incremental time controls

Rodney Barking brings you further original research on the playing rules of league chess in England. This time the subject is incremental time controls. This arose from an internal consideration of a potential attempt (not by the league committee) to amend the rules of the London League. Currently the rules stipulate a time control of 75 minutes for the game plus a 15-second increment from the start.

The main issue is whether the basic game time should be shortened, and the increment lengthened to 30 seconds a move. The point of the 30-second increment is to provide more thinking time in the later stages and to ensure that all moves are recorded throughout the game. The drawback is that reducing the basic game time may impair the quality of the chess played in the earlier stages.

Bear in mind the maths underlying the different ratios. In considering the effect of increments on the length of the playing session, the chess authorities assume that a game will last typically 60 moves. So a 15-second increment adds 1 minute for every 4 moves, whereas a 30-second increment adds 1 minute for every 2 moves. If the game lasts exactly 60 moves and both players use all the available time (without actually losing on time), then both G75 + 15s and G60 + 30s will result in a total playing session of exactly 3 hours.

There are 86 standardplay leagues in England (excluding online and junior leagues). Information on the playing rules is available online for 63 of these leagues. Of these, 52 provide for an incremental time control (either mandatory or the default option or simply an option) and 11 do not.

Almost all leagues with an incremental time control are based on a single session of play (49 out of 52). In these cases, this is the frequency of the different incremental controls (in ascending order of length).
G60 + 30s – 5
G65 + 30s – 1
G70 + 10s – 1
G70 + 15s – 2
G75 + 10s – 8
G75 + 15s – 6
G80 + 10s – 20
G80 + 15s – 2
G85 + 10s – 2
G110 + 10s – 1
G135 + 15s – 1.

The last two of these stand out from the rest, but they are afternoon leagues where more time is available.

In three leagues, the rules provide for two sessions of play. The first session is a set number of moves in a set time (eg 30 moves in 70 minutes). The second session is a guillotine with all remaining moves in a set time (eg all moves in a further 10 minutes). In all cases the increment applies from the start of the game.
G30/70 + all/10 + 10s – 1 (Coventry & District)
G35/70 + all/10 + 10s – 1 (Bedfordshire)
G40/100 + all/50 + 30s – 1 (4NCL).

There are some particular points I want to make about these results.

Although the most common time control is G80 + 10s, in one case known to Barking the relevant league moved from this to G75 + 15s and not the other way round. This was the Central London League, which made the change about 10 years ago. The league’s decision-makers agreed that the extra thinking time provided by an increment of 15 seconds rather than 10 seconds was more important than the reduction of the basic game time from 80 minutes to 75 minutes.

They may have been influenced by the early starting time in the Central London League (6.30pm). Late finishing was less of an issue. In contrast, the Surrey Border League rejected the same proposal (to move from G80 + 10s to G75 + 15s) at its AGM in 2022. Games in this league start an hour later, at 7.30pm, and the potentially-extended finishing time would have run up against venue closing time constraints in some cases.

The session length at the two London League central venues is limited to 3 hours and 30 minutes. This applies whatever time control is used. So although it is the case that a longer increment will prolong the game where more than 60 moves are played, that is not an argument against the longer increment, at the central venues at least. Barking knows of only one case where the game was not finished on the night. 

Finally, going all the way to G60 + 30s, in other words reducing the basic game time to 60 minutes, would have a direct implication for the default time allowed. As Barking has argued elsewhere, a league the size of London with regular transport problems requires a generous default time of 45 or 60 minutes and this is not easily accommodated within a basic 60-minute game time.