Team sport is an activity contested by different teams with their own sets of players in the course of a season which lasts less than one calendar year. This general definition applies regardless of which particular sport is involved – football, cricket, rugby… and chess.

In what circumstances, if any, can players turn out for different clubs in the same season? Each sport has its own rules. Football is one of the most prominent. There is a defined transfer window at the start of each season and in the middle of the season. During the window, players may transfer from one club to another. So it is possible for a footballer to play for two different clubs in the same season, but not at the same time. That’s how the league works anyway.

In the cup competition the rules are stricter. If you play a cup match for club A, and transfer to club B later in the season, you cannot play for club B in later rounds of the cup competition in the same season. You are said to be “cup-tied.” The point is to prevent eliminated clubs from selling their top players to another club with a view to that club increasing its chances of winning the cup. It’s an old rule and pre-dates the introduction of the transfer window, so maybe it’s anachronistic.

I carried out a survey of chess leagues in south east England (plus the 4NCL) to see whether there were any obvious patterns or predominant practice. There are 17 leagues. All the leagues where information is available restrict players moving around, though the extent of the restriction varies.

In six leagues, a player may not play for more than one club in the same season. These are the 4NCL, the Essex League, the Kent League, the London Public Service League, the Middlesex League, and the Portsmouth & District League. This is stated in the rules of most of these leagues. The London Public Service League is silent on the point, but its administrator has said that players are limited to one club and this may be made clear on the face of the rules from next season.

In another five leagues, a player may represent more than one club in the same season, in certain defined circumstances.

• The Central London League limits you to one club in divisions 1 and 2, but you may play for a different club in division 3 (presumably this means divisions 3 and 4 combined, now that the league is running a division 4).

• The London League limits you to one club in the divisional league (divisions 1 to 4), but you may play for one different club in the Major and Minor divisions combined, and yet another club in the Eastman Competition (formerly the Eastman Cup). These are effectively three different competitions in one league with some shared and some distinct rules.

• The Mid-Sussex League allows you to change clubs once a season, so you can play for a second club, but only if you have played fewer than five games for the first club.

• The Surrey League allows you to play for different clubs in different competitions, and the different divisions of the league count as separate competitions for this purpose, but only if you register for all the relevant clubs before the season starts. I tried to play for two different clubs in the Surrey League last season but was thwarted by the registration rule.

• The Thames Valley League allows you to play for two different clubs in one season, but not at the same time, and only in exceptional circumstances, which the rules do not define.

Finally, in a further six leagues, either the rules are silent on the issue or the rules are not available online. These are the Berkshire League, the City League (formerly the Combined London Banks and Insurance League), the Croydon & District League, the Hillingdon & District League, the Southampton League, and the Surrey Border League.

I suppose the point is to reinforce club loyalty – although that’s arguably less important these days, with the advent of clubs in the 4NCL and the London League whose composition reflects friendship or common interest rather than geographical ties. Also maybe the rules are there to prevent player anarchy. Imagine if Erling Haaland played for City v United one week, then decided to play for United v City the following week. This is the stuff of nightmares. You couldn’t run a league on that basis.

Even so, there are circumstances where a player has a genuine reason for turning out for two different clubs in the same season. For example the player may turn out a few times for club A, then resign from the club because of irreconcilable differences, and join club B instead. In effect the player is making a new start in the league. It seems unduly restrictive to prevent the player turning out for the new club until the following season.