Category Archives: Rules of play

Incremental time controls

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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.

Determining colours, and the default time

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As a former civil servant, I like to know what I’m talking about before I express an opinion on something. They call it Evidence-Based Decision-Making, or in other words, Knowledge is Power.

The London League is in the process of revising its rules. Back in October, an issue arose about whether teams should be selected on playing strength or in rating order. This blog carried out some research on the practice in other chess leagues the length and breadth of the land. The results appeared in the post The board order in league chess. Today we address two further issues: (1) how do you decide which team has white or black on each board; and (2) if you’re not there at the start, how much time do you have before you lose on default?

Determining colours

Traditionally the two teams would toss for colours and the winner would choose either white or black on top board (with the colours alternating down the board order). This was open to abuse in that if your player had prepared a particular line as white or black, winning the toss meant you could ensure the player got the preferred colour. So a refinement was to remove the choice and if you won the toss you automatically got a specified colour (in practice white) on top board.

Tossing for colours has its own issues: for example at what time before the scheduled start do you decide colours, and what happens if one team is not represented at the appointed time, for example running late in travelling to the venue? You could decide that the team which was there on time automatically had white on top board – at the risk of annoying the other team which might be late through no fault of its own.

So a further refinement – and this may reflect a modern trend towards simplification in procedure – was to eliminate the toss altogether and automatically allocate colours by a pre-determined principle, for example the home team or away team would always have white on odd boards.

Which brings us to the research. There are 86 chess leagues in England (excluding junior-only and online leagues). In 63 of these, the league rules are available online. (Previously it was 62, but one has emerged since then.) This is the frequency of the different options for determining colours.

  • home team has black on odd boards – 35
  • home team has white on odd boards – 5
  • toss for colours, winner chooses – 10
  • toss for colours, winner has white on odd boards – 9
  • not stated – 4.

In the London League, the fourth of these applies. Teams toss for colours and the winner automatically has white on odd boards.

The research shows that the clear preference in practice is for the home team to have black on odd boards. This must reflect the disadvantage to the away team in having to travel to the venue. This works fine if teams play their home matches at their home venue and their away matches at the opposition venue. But in some cases, including the London League, several clubs play all their matches at their home venue rather than a central league venue. Under this rule, their top board would have black in every game. That’s not a desirable outcome. The available information does not disclose – at least, not without a lot more digging – how many leagues feature clubs that always play at home and how many clubs are affected in each case. So we don’t know whether the London League is unique. If it’s not unique, the leagues which allocate colours automatically have not addressed the issue.

For the London League, a simple but unique solution has been proposed. This is that the home team has white on odd boards if the date of the match falls on days 1 to 15 of the month, and black on odd boards if it falls on days 16 to 31. Assuming a natural layout of the fixtures, roughly half of the fixtures would fall in each of the first and second halves of the month, so the colour distribution would be roughly even. At the time of posting, the proposal remains under consideration internally.

The default time

Here too, practice varies. The official FIDE Laws of Chess take a hardline approach:

6.6 a. Any player who arrives at the chessboard after the start of the session shall lose the game. Thus the default time is 0 minutes. The rules of a competition may specify otherwise.

This rule was introduced a number of years ago. It seems appropriate in official FIDE events, which are strictly controlled. In less formal conditions – applying in the typical weekend tournament in England, and in league chess played on a weekday evening – it would be completely impractical. Hence the discretion for local rules to specify otherwise. And they have done. There are no known cases in English league chess where the default time is 0 minutes.

In the 63 leagues where information is available, the default time is as shown below.

  • 30 minutes – 30
  • 45 minutes – 8
  • 60 minutes – 18
  • time control (75+ minutes) – 2
  • not stated – 5.

In the two leagues with a “time control” default system, the player may turn up at any time while the clock is still running, losing only when the time control is reached. In one case this is 75 minutes. In the other, a range of time controls are available and 75 minutes is the minimum.

The available information does not disclose the reasons for deciding on a particular default time in each league. Rules are rules and they rarely include explanatory material.

If you were developing a set of rules based on reason and logic, you might decide on a principled approach so that (for example) the default time was half the time available for the game. So if you had 90 minutes to make all your moves, you would have 45 minutes after the start to arrive at the board. Arriving just before the cut-off would still leave enough time for a sensible game.

An alternative approach would be to recognise that leagues operate in different circumstances and that no one solution would suit every league. If the league operated in a very small catchment area, and the travelling time to the venue was not significant, it might be appropriate to specify the short default time of 30 minutes. In other leagues, for example in large metropolitan areas, players might need longer to reach the venue. This may be what happens in practice – more detailed research would be needed to establish a correlation.

In the London League, which covers a large area, the current default time is 60 minutes. This is long enough for any reasonable journey. The downsides are, first, that if you’re present and your opponent is not, and you don’t know whether your opponent is running late or has simply forgotten there’s a match on that night, it’s a long time to wait for a no-show. And second, that if your opponent turns up just inside 60 minutes, with an incremental time control allowing a game time of 75 minutes, it’s practically impossible for the latecomer to play a serious game.

At its AGM in 2022, the London League considered a motion from one club to reduce the default time from 60 minutes to 30 minutes. This was no doubt motivated by the downsides of the longer default time. It was, however, clear from the debate that 30 minutes was in practice too short a default time for a league whose catchment area was the whole of London. Players could well miss the cut-off for no fault of their own, for example problems on public transport (and, more recently, one might add industrial action resulting a reduced service or none at all). The motion was defeated by 18 votes to 4.

During the debate, a compromise was suggested of a default time of 45 minutes. This reflected the experience of the person proposing the compromise (no prizes for guessing who that was) that players often turned up within 45 minutes of the start, but he did not recall anyone turning up between 45 and 60 minutes late. So nothing would be lost, and players wouldn’t have to wait a whole hour for a no-show. The amendment was defeated by 12 votes to 9. This was not because the majority of the clubs represented thought it was a bad idea in itself. Rather, it was tabled at no notice, and they had not been able to consult their membership. So in 2023, the proposal (and again this is still under consideration, well in advance of the summer AGM) is to reduce the default time from 60 minutes to 45 minutes.

Anyway, the lesson for any person of a sound mind is, Vote For Barking – You Know It Makes Sense.

Endgame tablebases

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I’m going to start this post by quoting an extract from the Wikipedia entry, since it says what I want to say and I don’t see the point of paraphrasing it.

An endgame tablebase is a computerized database that contains precalculated exhaustive analysis of chess endgame positions. It is typically used by a computer chess engine during play, or by a human or computer that is retrospectively analysing a game that has already been played.

The tablebase contains the game-theoretical value (win, loss, or draw) in each possible position, and how many moves it would take to achieve that result with perfect play. Thus, the tablebase acts as an oracle, always providing the optimal moves. Typically the database records each possible position with certain pieces remaining on the board, and the best moves with White to move and with Black to move.

Tablebases are generated by retrograde analysis, working backward from a checkmated position. By 2005, all chess positions with up to six pieces, including the two kings, had been solved. By August 2012, tablebases had solved chess for almost every position with up to seven pieces, but the positions with a lone king versus a king and five pieces were omitted because they were considered to be “rather obvious.”[1][2] These positions were included by August 2018.[3] As of 2022, work is still underway to solve all eight-piece positions.

Tablebases sometimes come with a name as a prefix, e.g. Nalimov, Lomonosov, Syzygy. Eugene Nalimov is a computer programmer who generated the first tablebases in the 1990s. Lomonosov is the name of a Russian supercomputer. Syzygy is an astronomical term describing the occurrence of three celestial bodies in a straight line. No, I don’t know what that has to do with chess either. Syzygy 7-piece tablebases are the most recent. These are used by the International Correspondence Chess Federation.

What is the practical use of a tablebase in correspondence chess? In my experience the tablebase is a means of bringing a game to an end quickly and so achieving a draw or a win, when your opponent cannot or will not see this, and particularly when he or she has slowed the game down in order to delay the inevitable. The ICCF rules allow you to claim a win or draw by reference to a tablebase where there are no more than seven pieces on the board. Here’s an example from one of Barking’s games earlier this year.

White: Maurizio Mangiarotti (1958), Black: Rodney Barking (1915).
D45: QGD Semi-Slav.

Yes, I know there are more than seven pieces… This was the position after White’s 41st move. Earlier I had given up my queen for a rook and bishop. As all the pieces are on one side of the board, and there are no passed pawns, Black can hold the draw easily enough and in fact the evaluation of one of the chess engines I use is 0.00. However, White can continue the game for quite a long time just by probing with the queen.

As I’m not winning this position, there’s no advantage to me in prolonging it. What’s the quickest way out? Answer: sacrifice some material…
41…Bxh4! 42.gxh4 Rxg4+ 43.Kh3 h5

Despite the material difference, this position is actually drawn. Black has constructed a fortress. There is no way the white king can penetrate Black’s defences. I offered a draw, which my opponent accepted.

The point that’s relevant to this post, and obviously I checked this before going nuclear, is that the position is a tablebase draw as well. I would have claimed a draw by reference to the ICCF tablebase if my opponent had not co-operated. This is what the tablebase evaluation looks like:

Interestingly, the various engines I use all evaluate this position differently. The strongest of them has White at +0.81 (approaching a clear advantage, but not yet winning). The weakest has White at +4.21 (a trivial win). I guess none of the engines has the 7-piece tablebase programmed in. Maybe that should not be a surprise as the storage size you need for a tablebase is absolutely huge.

I was going to give a further example, another game against my Austrian opponent Herr Wiesinger. We have reached a rook and pawn ending where the Austrian is totally lost. He knows this and has slowed the game down to a funereal pace. Unfortunately there are still eight pieces on the board so we are just out of tablebase range. I expect one of his pawns to drop off very soon (when he finally gets round to moving) and then it will be Goodnight Vienna.

So much for correspondence chess. What about tablebases in OTB chess? Now here’s a thing. Chess leagues are increasingly using incremental time controls. These carry the risk that a game may still be going on at the end of the playing session. Back in the day, if the two players couldn’t agree on the outcome, these games were resolved either by adjournment to a later date or by adjudication. Neither of these is ideal. Adjournments simply add to fixture congestion. Adjudications take the result of the game out of the hands of the players and transfer it to a third party (in Barking’s eyes this is a detestable practice).

The London League used to rely solely on adjournments, following a playing session of 30 moves in 90 minutes. Those days have gone. At some point in the past decade, the League introduced an incremental time control of G75 + 15. So far, there have been no documented cases of games being unresolved at the end of the playing session. But adjudication is available as a backup if needed.

This season, and as far as I know this is the first time this has happened in English league chess, tablebase decision-making has been introduced. If a game is unfinished, and there are no more than seven pieces on the board, the outcome is determined by reference to a tablebase rather than adjudication. This has the advantage of determining the outcome by objective rather subjective means since you know with certainty what will happen with perfect play on both sides, rather than relying on the human (no doubt computer-assisted) determination of the adjudicator. The relevant London League rule is as follows:

C8. UNFINISHED GAMES
C8.1 If any game is unfinished at the end of the session, both players and both captains shall record the position on the board. If the two sides cannot agree a result, then –

(a)  if no more than 7 pieces remain on the board, the result shall be determined by reference to a tablebase such as the Syzygy endgame tablebase at
https://syzygy-tables.info/?fen=4k3/8/8/8/8/8/8/4K3_w_-_-_0_1;

(b)  In other cases, both sides shall submit an adjudication claim to the league secretary together with a fee of £10. If only one claim is made, it shall be upheld without adjudication. Either side may appeal against an adjudication decision, providing supporting evidence, and on payment of a further fee of £10. The fees shall be returned to the relevant side if no adjudication is needed or if an appeal succeeds.

Whoever thought of this deserves a medal. Who says space can’t be conquered?!

The board order in league chess

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Rodney Barking likes to bring you original material, but will of course credit his sources when he draws on their work.

He particularly likes to bring you material which is based on original research and which has never been presented before.

So today: what criteria are used to determine the team board order in league chess in England? There are two main criteria. One is the order of playing strength. The other is the published ECF rating order. In either case, should the rules provide for displacement, such that a higher-rated player may play on a lower board than a lower-rated player?

Playing strength is more flexible and subjective. It can accommodate rating disparities more easily than a system based on the objective rating order. One can conceive of cases where (for example) a player rated 1950 is in better form than another player rated 2000 and should play on a higher board. But how far can this be stretched?

This may seem like a niche subject to which many players are indifferent. But it can give rise to heated argument, as Rodney has discovered on more than one occasion. Mostly recently in a difficult online exchange with another league official.

Now, people settle arguments in different ways. Some resort to brute force, or in extreme cases the power of the gun. Rodney prefers to use logic and reason, based on actual evidence. This is what you would expect since one commentator has characterised him as “an Oxbridge-educated civil servant”.

Rodney carried out an internet survey of leagues and playing rules overnight to obtain evidence about what provisions actually do apply. He surveyed all chess leagues in England (excluding online and junior-only) with an internet presence. There are 86 of these. These are the main points:

  • In 34 leagues, teams are in order of playing strength. 17 of these have a points differential and 17 do not.
  • In 21 leagues, teams are in rating order. 16 of these have a points differential and 5 do not.
  • In 7 leagues, there is no provision at all about the playing order.
  • In 24 leagues, the playing rules are not available online.
  • Where there is a rating points differential (33 leagues), this ranges from 38 to 150 points (equivalent to a grading difference of 5 to 20 points). 
  • The most common points differential is 75 points (16 leagues), followed by 100 points (7 leagues).

Rodney draws two conclusions from this. The first is that playing strength is a more common criterion than rating order. The second is that a points differential is much more strongly associated with leagues where teams are in rating order than in leagues based on playing strength. This is what one might expect given that there is a logical connection between rating order and rating differentials, whereas playing strength and rating differentials are of a different nature. If you’re going to allow a rating differential, you might as well have a basic rule of playing in rating order.

So Rodney has placed this on the table and awaits a response. In line with a famous work by an American evangelical Christian author (Josh McDowell), this is ‘Evidence That Demands a Verdict: Life-changing Truth for a Skeptical World.’