With the cricket season in full swing, Martin Vlietstra highlights some aspects of the laws of the game. Martin is on the active panel of qualified cricket umpires, and also comments frequently on articles posted on Metric Views.
The oldest known set of Laws of Cricket date back to 1744. Since then they have been revised several times. The 1947 revision, published at a time when all the major cricketing nations were part of the Commonwealth, was the last major revision in which all quantity specifications were expressed in imperial units only. Subsequent major revisions appeared in 1980, 2000 and 2017 and all use both metric and imperial units. Unfortunately, the way in which metric units have been introduced leaves much to be desired.
This article, which is intended to be informative in nature, will deal only with the specifications of the ball and of the bails as these provides the best insight into how specifications should be handled.
Prior to 1980, the law stated that a cricket ball was to be no less than 5½ ounces and no more than 5¾ ounces, and have a circumference of no less than 8 11/16 inches and no more than 9 inches. In 1980, smaller balls were specified for use in women’s cricket and for junior cricket while the specifications for the ball in men’s cricket were relaxed for lower level games. The new laws give the specifications as:
. Minimum Maximum
Top level men’s cricket
Weight 5½ ounces/ 155g. 5¾ ounces/163g.
Circumference 8-13/16 inches/22.4 cm. 9 inches/22.9 cm.
Men’s Grades 2-4
Weight 5-5/16 ounces/150g. 5-13/16 ounces/165g.
Circumference 8-11/16 inches/22.0cm. 9-1/16 inches/23.0cm.
Weight 4-15/16 ounces/140g. 5-5/16 ounces/150g.
Circumference 8-1/4 inches/21.0cm. 8-7/8 inches/22.5cm.
Weight 4-5/16 ounces/133g. 5-1/16 ounces/143g.
Circumference 8-1/16 inches/20.5cm. 8-11/16 inches/22.0cm.
(This article follows to convention of the law book, which had full stops after the metric unit symbols and no space between the value and the unit.)
It is quite clear from these figures that in 1980 the Marylebone Cricket Club (MCC), the governing body of cricket, intended to move over to using metric units. Unfortunately the laws do not specify which is the authoritative unit of measure – the Imperial unit or the metric unit. Had they written “5½ ounces (155 g)” or “140 g (4-15/16 ounces)” it would have been clear which was the authoritative unit of measure and which was the supplementary unit of measure. The revision published in 2000 was identical except that relaxations permitted in men’s level 2 to level 4 cricket was dropped. In the 2017 version, vulgar fractions were replaced by decimal fractions round to two significant figures, for example, the minimum circumference of a cricket ball became “8.81 in/22.4cm”. (At least the erroneous dot after the symbol was removed).
My own suggestion is that in cases where the MCC wish the Imperial unit to be the definitive value, the specification should quote the Imperial unit first followed by the metric unit in brackets. In cases where the metric unit is the definitive unit, there is no need to quote the equivalent Imperial unit as it is unlikely that anybody will need to use it. I would also suggest the use of millimetres rather than centimetres so as to avoid decimal points.
For those unfamiliar with cricket, these are the two short timber rods that sit on top of the three timber stumps. The aim of the bowler is to dislodge them with the ball; the aim of the batsman (or woman) is to prevent this.
In the 1947 version of the laws, the specification of the bail was that it should be no more than 4-3/8 inches in length and should project no more than ½ inch above the stumps. In the 2000 and 2017 versions, the bails were specified much more fully as follows:
. 2000 Imperial 2017 Imperial Metric
Total length 4-5/16 in 4.31 in 10.95 cm
Barrel 2-1/8 in 2.13 in 5.40 cm
Shorter spigot 13/16 in 0.81 in 2.06 cm
Longer spigot 1-3/8 in 1.38 in 3.50 cm
Neither the diameters of the barrel or spigot nor the diameter of the grooves on the stumps were specified except that the bails should not project more than “½ in/1.27 cm” above the stumps. This is all very well when stumps and bails are made by the same manufacturers, but can cause problems where different manufacturers are involved– in fact top-class umpires often carry their own set of bails. The laws do however imply that the maximum diameter of the barrel is one inch (2.54 cm), but no minimum is quoted.
The observant reader will notice that in the 2000 Imperial set of dimensions, the sum of the lengths of both spigots and the barrel equal the total length of the bail. This is not the case in either the 2017 Imperial version or the metric version of the laws.
These specifications carry a number of other questions, notably those related to manufacturing tolerances. Since the tightest specification in the 2000 Imperial dimensions is to the nearest 1/16 in, it can reasonably be assumed that there is an implied tolerance of 1/32 in (about 0.8 mm). The 2017 Imperial specification implies a tolerance of 0.005 in (0.13 mm) while the metric specification implies a tolerance of 0.05 mm.
My own suggestion is that Imperial units should be dispensed with entirely and that the length of the bail should be between 108 and 110 mm, the barrel between 53 and 55 mm, the longer spigot between 34 and 36 mm and the shorter spigot between 20 and 22 mm. In addition, I would suggest that the diameter of the barrel should be between 25 and 26 mm and the diameter of the spigots between 9 and 10 mm. I would also suggest that the diameter of the grooves should be between 12 and 13 mm.
The bat and the crease markings
The specifications of the bat and crease makings follow a similar pattern, but as this article is primarily about the use of metric and Imperial units rather than the laws of cricket, the interested reader is referred to the Laws of Cricket on the MCC website. The shortcomings in those parts of the law are much as described earlier.