Contents...

• Definitions and Abbreviations
• Introduction
• Small Separation Strokes
• How to Referee Such Strokes
• Exercising Judgement

Definitions and Abbreviations

All references to the GC Rules are to the 6th Edition.

Diagram 1 below defines the abbreviations used in this guidance:

• Aiming Angle to the line of ball centres (AA), measured in degrees.
• Initial Separation (IS) of the balls, measured in millimetres.
• Departure Angle (DA) - the angle, measured in degrees, at which the balls separate after impact.
• Striker's Ball (SB) - the ball to be struck by the mallet - black ball in the diagram.
• Object Ball (OB) - the ball being moved by SB - red ball in diagram.

Diagram 1 - Abbreviations used in Short-Range Clearance Guidance

Introduction

Paragraph 4.1 of Appendix 5 of the GC Rules sets out the guidance (the 8:1 'rule') on a stroke that involves hitting a ball towards another ball more than 4 mm away, along, or close to, their line of centres. This is soundly based on the super slow-motion videos made by The Croquet Association at Bowden in 2006.

Paragraph 4.2 of Appendix 5 addresses balls played at an angle to their line of centres.

Since that guidance was produced, to assist in adjudicating strokes involving balls less than 4 mm apart (defined as 'very small separation strokes'), a set of trigonometrical calculations have been used to identify the angles required to achieve 4 mm effective separation distances at different Initial Separations. The results are shown in Chart 1 below:

Chart 1 - Minimum Aiming Angle for a range of Initial Separations to Achieve a Clean Stroke.

Playing very small separation strokes at these, or greater, angles will thus avoid Crush Faults, because generally the striker's ball only stays in contact with mallet for about 4 mm.

The existence of this chart allows this guidance to override the final sentence of Para 4.2.2 of Appendix 5 "If the separation is less than 4 mm, the angle at which balls depart should be approaching 90 degrees to be sure of a lawful stroke.". Instead, the more consistent measure, the Aiming Angle of the mallet, should now be used to determine the ruling.

Small Separation Strokes

This supplementary, web-based guidance includes two tables, Tables A (based on assessing the Departure Angle) and B (based on observing the Aiming Angle of the mallet), below, to provide easy-to-use ready reckoners for adjudicating all Small Separation Strokes:

Table A should be used to adjudicate all strokes involving balls with small initial separations, unless the Initial Separation is less than 4 mm (i.e. a Very Small Initial Separation), when Table B is the relevant table.

This guidance also includes how to referee a Small Separation Stroke and the factors applicable when exercising judgement.

How to Referee Such Strokes

1. Ask the player what they intend to do. The referee should establish:
   1. What is the player's intended line of aim and hence what AA they intend.
   2. The type of stroke that the player intends to play (i.e. firm/gentle, roll/stun/slice etc). While this is not a factor bearing on the lawfulness of the stroke, it will assist the referee is deciding where to stand to observe and what outcome to expect.
2. Mark the balls' positions. It may also be useful to mark the intended AA using a marker placed behind the player.
3. Check the separation between the balls along the line of centres. If the separation is less than 4 mm, be prepared to use Table B in adjudicating the stroke.
4. Ask the player to play the stroke.
5. Watch the stroke - was it along the intended AA; was it a well-executed shot?
6. Apply the guidance given (using the appropriate Table A or Table B) to decide whether or not to declare a Fault under Rule 11.2.4 or 11.2.6.

Exercising Judgement

Note always that poorly played strokes with excessive or lazy follow-through will be likely to cause a Fault even in circumstances when a well-executed stop (stun) shot would not - this must be considered when refereeing a stroke.

Table B above identifies with yellow-coloured cells some marginal circumstances when a referee will need to rely more on their experience in making a judgment based on whether a Fault was more likely than not (in accordance with Rule 11.3.1).

For angled strokes, mindful of the minimum Aiming Angle require to achieve a 4 mm effective separation distance, as defined above (see Chart 1), referees will need to use all of:

• The Initial Separation.
• The Aiming Angle.
• The way the balls moved, including the Departure Angle (see below).
• The sound (N.B. not a very reliable guide).
• What happened with the mallet's follow through.
• Any interaction with a hoop / peg.

When played correctly at extreme angles, the Object Ball will not move very far at all - if it moves a significant distance, then there is likely to have been a Fault under Rule 11.2.6.