Understanding Lawn Bowls

General
Game
Scoring
Bias of bowls
Variations of play

General
Bowls is a sport in which the goal is to roll slightly asymmetric balls, called bowls, closest to a smaller, normally white, bowl called the "jack" or "kitty". Bowls, either flat- or crown-green, is usually played outdoors, on grass and synthetic surfaces. Flat-green bowls can also be played indoors on synthetic surfaces. Both variants are collectively known as "lawn bowls".
Bowls belongs to the boules sport family, and so is related to bocce and pétanque. It is most popular in Australia, New Zealand (where the playing surface is predominately cotula), the United Kingdom, and in other Commonwealth nations.
Lawn bowls is usually played on a large, rectangular, precisely levelled and manicured grass or synthetic surface known as a bowling green which is divided into parallel playing strips called rinks. An indoor variation on carpet is also played. In the simplest competition, singles, one of the two opponents flips a coin to see who wins the "mat" and begins a segment of the competition (in bowling parlance, an "end"), by placing the mat and rolling the jack to the other end of the green to serve as a target. Once it has come to rest, the jack is aligned to the centre of the rink and the players take turns to roll their bowls from the mat towards the jack and thereby build up the "head".
A bowl may curve outside the rink boundary on its path, but must come to rest within the rink boundary to remain in play. Bowls falling into the ditch are dead and removed from play, except in the event when one has "touched" the jack on its way. "Touchers" are marked with chalk and remain alive in play even though they are in the ditch. Similarly if the jack is knocked into the ditch it is still alive unless it is out of bounds to the side resulting in a "dead" end which is replayed though according to international rules the jack is "respotted" to the centre of the rink and the end is continued. After each competitor has delivered all of their bowls (four each in singles and pairs, three each in triples, and two bowls each in fours), the distance of the closest bowls to the jack is determined (the jack may have been displaced) and points, called "shots", are awarded for each bowl which a competitor has closer than the opponent's nearest to the jack. For instance, if a competitor has bowled two bowls closer to the jack than their opponent's nearest, they are awarded two shots. The exercise is then repeated for the next end, a game of bowls typically being of twenty one ends.
Lawn bowls is played on grass and variations from green to green are common. Greens come in all shapes and sizes, fast, slow, big crown, small crown etc.
Scoring
Scoring systems vary from competition to competition. Games can be decided when:
•    a player in a singles game reaches a specified target number of shots (usually 21 or 25).
•    a team (pair, triple or four) has the higher score after a specified number of ends.
Games to a specified number of ends may also be drawn. The draw may stand, or the opponents may be required to play an extra end to decide the winner. These provisions are always published beforehand in the event's Conditions of Play.
In the Laws of the Sport of Bowls the winner in a singles game is the first player to score 21 shots. In all other disciplines (pairs, triples, fours) the winner is the team who has scored the most shots after 18 ends of play. Often local tournaments will play shorter games (often 10 or 12 ends). Some competitions use a "set" scoring system, with the first to seven points awarded a set in a best-or-three or best-of-five set match. As well as singles competition, there can be two (pairs), three (triples) and four-player (fours) teams. In these, teams bowl alternately, with each player within a team bowling all their bowls, then handing over to the next player. The team captain or "skip" always plays last and is instrumental in directing his team's shots and tactics. The current method of scoring in the professional tour (World Bowls Tour) is sets. Each set consists of nine ends and the player with the most shots at the end of a set wins the set. If the score is tied the set is halved. If a player wins two sets, or gets a win and a tie, that player wins the game. If each player wins a set, or both sets end tied, there is a 3-end tiebreaker to determine a winner.
Bowls are designed to travel a curved path because of a weight bias which was originally produced by inserting weights in one side of the bowl. This is no longer permitted by the rules and bias is now produced entirely by the shape of the bowl. A bowler determines the bias direction of the bowl in his hand by a dimple or symbol on one side. Regulations determine the minimum bias allowed, and the range of diameters (11.6 to 13.1 cm), but within these rules bowlers can and do choose bowls to suit their own preference. They were originally made from lignum vitae, a dense wood giving rise to the term "woods" for bowls, but are now more typically made of a hard plastic composite material.
Bowls were once only available coloured black or brown but they are now available in a variety of colours including a range of fluorescent hues. They have unique symbol markings engraved on them for identification. Since many bowls look the same, coloured, adhesive stickers or labels are also used to mark the bowls of each team in bowls matches. Some local associations agree specific colours for stickers for each of the clubs in their area. Provincial or national colours are often assigned in national and international competitions. These stickers are used by officials to distinguish teams.
Bowls have symbols unique to the set of four for identification. The side of the bowl with a larger symbol within a circle indicates the side away from the bias. That side with a smaller symbol within a smaller circle is the bias side toward which the bowl will turn. It is not uncommon for players to deliver a "wrong bias" shot from time to time and see their carefully aimed bowl crossing neighbouring rinks rather than heading towards their jack.
When bowling there are several types of delivery. "Draw" shots are those where the bowl is rolled to a specific location without causing too much disturbance of bowls already in the head. For a right-handed bowler, "forehand draw" or "finger peg" is initially aimed to the right of the jack, and curves in to the left. The same bowler can deliver a "backhand draw" or "thumb peg" by turning the bowl over in his hand and curving it the opposite way, from left to right. In both cases, the bowl is rolled as close to the jack as possible, unless tactics demand otherwise. A "drive" or "fire" or "strike" involves bowling with force with the aim of knocking either the jack or a specific bowl out of play - and with the drive's speed, there is virtually no noticeable (or, at least, much less) curve on the shot. An "upshot" or "yard on" shot involves delivering the bowl with an extra degree of weight (often referred to as "controlled" weight or "rambler"), enough to displace the jack or disturb other bowls in the head without killing the end. A "block" shot is one that is intentionally placed short to defend from a drive or to stop an oppositions draw shot. The challenge in all these shots is to be able to adjust line and length accordingly, the faster the delivery, the narrower the line or "green".
Particularly in team competition there can be a large number of bowls on the green towards the conclusion of the end, and this gives rise to complex tactics. Teams "holding shot" with the closest bowl will often make their subsequent shots not with the goal of placing the bowl near the jack, but in positions to make it difficult for opponents to get their bowls into the head, or to places where the jack might be deflected to if the opponent attempts to disturb the head.
There are many different ways to set up the game. Crown Green Bowling utilises the entire green. A player can send the jack anywhere on the green in this game and the green itself is more akin to a golf green, with lots of undulation.
Singles, triples and fours and Australian pairs are some ways the game can be played. In singles, two people play against each other and the first to win to either 21, 25 or 31 shots (how many bowls of ones are closest to the white jack or kitty are shots). The controlling body sets the game to either 21, 25 or 31. An additional scoring method is set play. This comprises two sets over nine ends, an end being the completion of both players delivering all their bowls. Should a player win a set each, they then play a further 3 ends that will decide the winner.
Pairs allows both people on a team to play Skip and Lead. The lead throws two bowls, the skip delivers two, then the lead delivers his remaining two, the skip then delivers his remaining two bowls. Each end, the leads and skips switch positions. This is played over 21 ends or sets play. Triples is with three players while Fours is with four players in each team and is played over 21 ends.