More Details on Curling Basics  


     The origins of curling are lost in the mists of time.  Centuries ago, long before global warming was thought of, Scottish winters were a lot colder than they are now.  The ground would frequently be frozen solid for days or even weeks on end, to the point where it would be impossible to work the soil.  What better way to fill in the hours when work wasn't possible than to take advantage of the wintry conditions - frozen ponds and streams?  Early games must have consisted of aiming rocks at a target on the ice, with very little by way of rules - any size or shape of stone, any number of players, any number of stones per player, any size of "rink".  During the eighteenth century, the rules became more formalised, and are now controlled by the Royal Caledonian Curling Club (RCCC).


 The Curling Rink
     A curling rink consists of one or more "sheets", each of which is laid out as in the diagram above.  At each end of the sheet is a small rubber-covered block embedded in the ice called a "hack".  The hack is a foot stop, which provides purchase for the curlers to slide out along the ice and deliver the stone.  The distance from hack to hack is 138 feet ( 42.1 metres), while the width of the sheet is about 14 feet (4.3 metres).  6 feet (1.8 metres) in from the hack is a 12 feet (3.7 metres) diameter circle, called the "house".  The house is usually coloured in with concentric circles, as in the diagram above.  The coloured circles don't affect point scoring - they are there merely to aid naked eye judgement of which stones are nearest the centre spot of the circles, or "tee".  A stone must at least touch the outer circle to be eligible for a point.  ; The "hog line" is a line drawn across the sheet 21 feet (6.4 metres) beyond the centre of the circles.  When delivering a stone, the curler must release the stone before reaching the near hog line, and the stone must cross the far hog line to remain in play.


 Curling Stones
       A curling stone is made of polished granite, and weighs between 42 and 44 pounds (19.1 - 20.0 kilograms).  It is about 10 inches (25 cm) in diameter and 5 inches (13 cm) high.  A handle, usually made of tough plastic, is bolted to the stone.  The picture shows a lighter coloured band running round the rim of the stone.  This is the "striking band", being a slightly rougher, flatter surface which allows a greater contact area when the stone hits another one, thus greatly reducing the chance of damage to the stone itself.
     The underside of the stone is not flat - it is slightly concave, so the stone runs across the ice on a narrow circular ring (the "running band"), rather than on a large circular area.  This reduced area of contact with the ice allows the stone to go further, and also to pick up more "curl".

Each player delivers 2 stones per end, so all together 16 stones are required per sheet.  They are carefully manufactured to ensure matched sets in terms of weight, shape, and size.

The player determines the direction of the curl when he / she delivers the stone by turning the handle on the stone slightly to impart a slow spin (ideally, about 2 complete revolutions from "tee to tee").  An anticlockwise spin (or "out-turn" for a right-handed player) causes the stone to curl from right to left as the player sees it.  A clockwise spin (or "in-turn") causes the stone to curl from left to right.


 The Ice, and Sweeping

Pebbling the Ice

(The "pebbler" walks backwards to avoid his
footprints disturbing the evenness of the spray)
  Slight imperfections in the ice surface will cause a stone having no spin (or no "handle") to move in an unpredictable path.  A stone with a spin is much more predictable, and to an extent controllable after it has left the player's hand.  A significant element in the rate of curl is the ice surface.  Before each game, the ice is covered with a fine spray of water - a process known as "pebbling".  The droplets instantly freeze on contact with the ice, so the ice surface becomes covered with a series of microscopic bumps.  The result of this is that the contact area between the curling stone and the ice, already small because of the effect of the running band on the stone, is reduced still further.  Perfectly flat ice which has been well pebbled should allow a stone played at "tee weight" (i.e. played to come to rest at the centre of the circles at the far end) to curl laterally about 3 feet (0.9 metres) from the straight line.

Sweeping the ice in front of the stone as it moves along the ice originally came from the outdoor game - it removed small debris from the ice so as not to impede or alter the path of the stone.  Two other effects became noticeable, particularly when the game moved to indoor rinks.  The friction of vigorous sweeping causes a brief melting of some of the pebble bumps, which results in the stone travelling further before it slows down.  It also delays the onset and magnitude of the curl.  Sweeping can therefore keep a stone straighter, and / or make it travel further.


 Curling Equipment

  The equipment needed to curl is very simple.  Firstly, a set of 16 stones is required per sheet.  These are supplied by the ice rink where the game is taking place, although for outdoor games (sadly all too rare nowadays), players must find / borrow / steal their own stones.

Secondly, you will need a pair of curling shoes.  These resemble stout trainers, but have one important difference - the soles.  For a right-handed person, the sole of the left shoe is made of Teflon, to allow the player to slide easily when delivering a stone or sweeping.  By way of contrast, the sole of the right shoe provides a good grip on the ice, to provide purchase on the ice when sweeping.  Curling shoes usually come with a "kipper" (a slip-on cover for the Teflon-soled shoe, so called because it resembles a kipper in size, shape, and even colour).  When this is worn, it allows easy and safe walking on the ice - particularly useful for the skip.

Thirdly, you should wear reasonably loose fitting trousers or slacks (there's a fair amount of bending and stretching involved), a warm sweater, and thick socks - ice rinks can get pretty cold!

Finally, you will need a curling brush for sweeping the ice under the skip's direction, and to assist balance when delivering the stone.  Again, ice rinks will supply brushes, but most curlers like to have their own brush. 



 The Structure of a Curling Team
       A curling team consists of four players - lead, second, third, and skip.  In each end, all four team members play in this sequence, and deliver two stones each, alternating with his / her opposite number in the opposing team.  So at any time during the end, one member is delivering a stone, one is skipping, and two are sweeping.  The adjacent diagram shows the order of play for both teams during an end.

Like a quarterback in American football, the skip literally "calls the shots" that the rest of the team must play.  Before each stone is played, the skip will indicate at what speed the stone should be played, and where the played stone should stop.  He / she will place the brush in the position to be aimed at (allowing for the curl), and indicate the "handle" (clockwise or anticlockwise) to be played.  Once the stone has been delivered, the skip will call the sweepers to sweep if necessary, to straighten the path of the stone and / or make it travel further.  Skipping therefore requires experience, judgement, and tactical knowledge.


 Delivery of a Curling Stone
          Just as for a golf swing, a good and repeatable delivery technique is a fundamentally important part of consistent shot making in curling.  The video screen on the left will show how it's done, while the photo sequence below describes the phases of the delivery in detail.

(Note: You'll need Windows MediaPlayer to view this video.  Click the ["Play"] button below the video screen to download and play the clip.  The download phase should take about 10 seconds via broadband, or up to 2 minutes via dial-up connection, during which the video screen will either show the MediaPlayer logo or stay blank.  The clip should then start to play automatically.)
(Clicking on any photo in the sequence below will show the corresponding full size picture.)
  Initially, the curler takes up a sort of crouch - the right foot resting in the hack, both legs bent at the knee with the right knee lower than the left, so that he / she is almost sitting on the right heel, and aiming at the skip's broom.  The curling stone is resting on the ice in front of the curler, with the handle held in the right hand.  At this point, the curling brush is used for balance, and is held in the left hand, with the brush head on the ice, and the brush handle across the curler's back, providing a tripod of right foot, left foot, and brush head, for balance and stability.  Finally, the curler's shoulders should be square on to the line of the broom held by his / her skip.
  The stone is then pulled backward across the ice, while at the same time the right leg straightens, the left leg slides backwards,and the brush moves toward the body.  (Note that current teaching suggests the stone should not be raised off the ice as in the traditional back-swing delivery method.  The "no back-swing delivery" style produces more consistent shot-making, with the vagaries of backswing removed - all the power comes from the push-off by the right leg).
  The curler then pushes against the hack with his / her right leg. 

The curler's body moves forward and downwards as the stone slides forward.

  Curler, brush, and stone now glide down the ice together, aiming squarely for the skip's broom.
  The stone must be released before the near hog line, otherwise it's a foul shot.  At the point of release, the handle on the stone is gently turned clockwise or anticlockwise, as indicated by the skip.
  The curler "follows through" after the delivery, and may well slide well over the hogline, with his / her eye still on the stone.

From now on, it's up to the sweepers and the skip to assist the stone to its destination.


 Curling Shots
     There are many shots in curling, but most of them are variations on the three basics - the draw, the guard, and the strike.
The draw is the most basic shot in curling.  The aim is to place the stone in the house, and the picture shows a near perfect draw to the tee.  But at this stage, it has no protection - it's a sitting duck.  Vigorous sweeping of a draw can make it travel up to 10 feet further.
Guarding involves delivering a stone at slightly less than draw weight so that it blocks the path to the target stone.  Positioning of the guard can be crucial - it may be perfectly in line, but if it's too far away from the target stone, the opposition can draw round the guard.  If it's too close, the opposition may be able to strike both stones out simultaneously.
The prime objective of the strike is to remove the opponent's stone (or stones if the alignment is right).  It is therefore played at a heavier weight than a draw.  The picture shows a yellow-team stone about to be struck out by the green-team one.  A secondary objective may be to leave the green-team stone in a good position in the house.  In this case, fine judgement is needed to ensure that the green stone hits the yellow at just the correct angle.  Good sweepers can be worth their weight in gold!
     Excellent animations of these three shots, together with animations of many other shots, can be seen on the Curling Basics website.  The Curling Basics website also has a full description of the rules of Curling.


 Curling Strategy and Tactics
     Curling is sometimes referred to as "Chess on Ice" - an exaggeration perhaps, but there are similarities, particularly when the game is played at the highest level.  The skip needs to think a lot about the shots to be played to maximise advantage for his / her team, and at the same time make life difficult for the opponents.  Likely counter-moves by the opposition need to be considered before nominating the next shot.  Books have been written on Curling tactics - including the excellent "Curling Tactics" by Scottish ex-World Champion Hammy McMillan, (and other contributors).  This isn't the place for a detailed study of strategy and tactics, but here are three examples to whet your appetite.
  1. Aiming to place a stone on the tee may not be a good idea if you know your immediate opponent will strike it out 9 times out of 10.  Much better to place the stone further away from the centre, but behind the cover of a guard. 

  2. If your team will not be playing the last stone at a particular end, it's not a good idea to aim straight for the tee - those demon strikers in the other team will just keep taking your team's shots out.  Much better to clutter up the front of the house with guards, and hope that the 3rd or skip will "steal" 1 or 2 shots by "promoting" a guard, or maybe by drawing round it. 

  3. Perhaps at that crucial second-last end, the score is all tied, and with the last stone, you have an open draw for a single shot lead.  Do you take it?  If you do, you lose the advantage of last stone at the last end, and your opponents may just get the two shots they need.  If you don't take the open draw and just leave the stone well short, the score is still tied, but you hang on to last stone at the last end.  You may make the single shot you need for victory - if your wily opponents haven't already got there first and blocked the way in.  Decisions, decisions ....
Bridge of Weir Curling Club - 2002