Scrum, Lineout and Set-Piece Retention Calculator
Rugby Union Scrum and Lineout Retention
A rugby union side’s set-piece retention — own scrums won, own lineouts won, and the two pooled — on World Rugby’s own published definitions of when a scrum and a lineout are won and lost. Rugby league is a separate sport with no lineout at all, so this page does not describe it.
Set-piece retention
World Rugby's own definitions11 own scrums won from 12, and 14 own lineouts won from 16
Formula
- own scrum won
- World Rugby’s words: “A scrum is won when the ball is channelled to the back of the scrum of the feeding team and normal play resumes”, with a penalty or free kick against the non-feeding side also a win. Lost: “A scrum is lost when the ball goes beyond the feet of the opposition’s number 8 and the opposition obtains possession”, and also where the scrum wheels past 90 degrees or the feeding side concedes a penalty
- own lineout won
- “A lineout is won when a team gains possession from the lineout”, won quick throw-ins included; “A lineout is lost when a team loses possession from the lineout”, which also covers a penalty, a knock-on and a throw that is not straight. World Rugby keeps “Lineout Contested” — where “the opposition contest in the air” — as a separate category, so a contested lineout is not a lost one
- the percentage itself
- NOT World Rugby’s. Its definitions run to four sections and name no success rate, efficiency or percentage of any kind: the body defines won and lost and leaves the ratio to whoever computes it. This page’s convention is own events retained over own events held, which is the obvious one and is still a convention
- the breakdown, on the same principle
- World Rugby also defines “Own ruck won” and “Own maul won” the same way — possession retained when the ball leaves the ruck or maul — so a set piece and a breakdown can be counted alike. The body stops short of pooling them and so does this page: the contests have different base rates and an average of two says less than either
Worked example
11 own scrums won from 12, and 14 own lineouts won from 16
12 + 16 = 28 own set pieces; 11 + 14 = 25 retained; 100 x 25 / 28 = 89.3%
Split out: 11 / 12 = 91.7% at the scrum and 14 / 16 = 87.5% at the lineout — and lineouts are 16 of the 28, so the pooled figure is weighted toward the weaker contest simply because there are more of them
It is a rate, both ways. Double every count, 22 from 24 and 28 from 32, and the answer stays 89.3%. Halve the denominator while keeping the numerator: 7 from 14 is 50% against 7 from 7 at 100%, so halving the denominator doubles the figure exactly
A single match is a tiny denominator: a Test side may hold a dozen scrums and sixteen lineouts, so one lost throw moves the lineout figure by more than six points and the pooled figure by three and a half
The refusals: no scrums and no lineouts at all gives no figure rather than nought, and 13 scrums won from 12 held is refused outright rather than printed as 108.3%
World Rugby’s own definitions, in its own words
| The event | World Rugby’s definition |
|---|---|
| Own Scrum won | “A scrum is won when the ball is channelled to the back of the scrum of the feeding team and normal play resumes” |
| Own Scrum lost | “A scrum is lost when the ball goes beyond the feet of the opposition’s number 8 and the opposition obtains possession” |
| Scrum Reset On Own Feed | “A reset occurs when the referee asks for the an incomplete scrum to be reformed” — the typo is the source’s |
| Own Line-out won | “A lineout is won when a team gains possession from the lineout” |
| Own lineout lost | “A lineout is lost when a team loses possession from the lineout” |
| Own Line-out lost due to not straight throw | “The line-out is lost when the player throwing the ball into the line-out does not throw the ball straight down the middle” |
| Lineout Contested | “A lineout is comtested when the ball is thrown into the lineout and the opposition contest in the air” — again the source’s typo |
| Own ruck won | “A ruck is won when a team in possession at the start of the ruck retains possession when the ball leaves the ruck” |
| Own maul won | “A maul is won when a team in possession at the start of the maul retains possession when the ball leaves the maul” |
| A set-piece success percentage | NOT DEFINED ANYWHERE in the list |
Why this page does not cover rugby league
| Rugby union | Rugby league | |
|---|---|---|
| The lineout | a contest for a throw-in from touch, with lineout numbers and air contest both defined by World Rugby | does not exist |
| Restart after the ball goes into touch | a lineout | a play-the-ball, since the Australian Rugby League Commission’s December 2020 changes |
| The scrum | a contest, with collapses, resets and wheels past 90 degrees all separately defined | a restart; scrums were suspended entirely in 2021 on medical advice about Covid-19 risk, the RFL saying they could return “certainly at Betfred Super League level” |
| Players binding in a scrum | eight | “No more than six players on each team shall assist in the formation of a scrum” — Section 12, Law 3 |
| The unit of possession | the set piece and the breakdown | the set of six tackles — Section 11, Law 7(a) allows “five successive play-the-balls” |
| So the figure to compute instead | this page | tackle count and completion, on the tackle calculator |
The body defines the events and leaves the ratio to you
This page is about rugby union, and only rugby union. The body whose documents it quotes is World Rugby, which governs the fifteen-a-side game. Rugby league is a separate sport with a separate governing body, the International Rugby League, and its own laws; it is not what this page measures and its figures cannot be read off it. The two codes separated in 1895, and this site keeps every rugby page explicit about which of them it describes, because the same word very often names two different things in them.
This is one of the few pages in this section where the governing body publishes the definitions. World Rugby maintains a Game Analysis Definitions list, in sections headed Scoring, General Play, Set Piece and Sanctions, and it states in its own words when a scrum is won — “when the ball is channelled to the back of the scrum of the feeding team and normal play resumes” — and when it is lost: “when the ball goes beyond the feet of the opposition’s number 8 and the opposition obtains possession”. A lineout “is won when a team gains possession from the lineout”. Those sentences are the numerator and the denominator of this page, and they come from the body rather than from a statistics vendor or from this site’s own reasoning.
What the body does not publish is the percentage, and that distinction is the point. Nowhere in that list is there a success rate, an efficiency or a percentage of any kind — not for a scrum, not for a lineout, not for a tackle. World Rugby defines won and lost and stops. So “91.7% at the scrum” is a convention built on official events, and the convention is this page’s: own set pieces retained divided by own set pieces held. It is the obvious convention and probably the one everybody uses, and it is still a convention. Where a broadcaster’s figure differs from this page’s, the most likely reason is a different treatment of a penalty awarded at the set piece, which World Rugby counts as a win for the side that did not concede it.
“Own” is doing real work in all four definitions. A retention figure is about the set pieces your side fed or threw into, not every set piece in the match. Mixing the two produces a number that moves when the opposition’s throwing improves, which measures nothing your side did. The same applies to the pooled figure more subtly: lineouts usually outnumber scrums, so the pooled number is weighted toward the lineout simply because there are more of them. In the worked example, sixteen of twenty-eight set pieces are lineouts, and the pooled 89.3% sits much closer to the lineout’s 87.5% than to the scrum’s 91.7% for that reason and no other.
A contested lineout is not a lost lineout, and World Rugby keeps them apart. “Lineout Contested” is its own category — “when the ball is thrown into the lineout and the opposition contest in the air” — alongside the count of players taking part and a named sub-category for a lineout lost because the throw was not straight. The scrum has the same granularity: collapses on your own feed, resets at the referee’s call, a scrum won through a wheel past ninety degrees, and the time taken to complete one scrum measured from the whistle. None of that detail is in a retention percentage, which is worth knowing before concluding that a 90% scrum is a good scrum — a pack can retain every feed while conceding resets and free kicks all afternoon.
For the kicks that lineout positions often become, see the goal kicking success calculator; for rugby league’s unit of possession, which is a set of six tackles rather than a set piece, see the tackle count and completion calculator; and for the ground those lineouts are thrown on, including the fifteen-metre line a union lineout is bounded by, see the pitch dimensions interpreter.
Every number on this page is arithmetic on a count, a law or a regulation that a governing body or a competition publishes, and each one names where it was read. Nothing here is a commercial prediction, and no page in this section is.
Frequently asked questions
How is rugby lineout success calculated?
Own lineouts won divided by own lineouts thrown. World Rugby defines the event — “A lineout is won when a team gains possession from the lineout” — and does not define the percentage, so the ratio is a convention built on an official event rather than an official statistic.
Does World Rugby publish a set-piece success rate?
No. Its Game Analysis Definitions give won and lost for scrums, lineouts, rucks and mauls in the body’s own words, and name no percentage, success rate or efficiency anywhere in four sections. This page says so rather than implying its figure is official.
Is a penalty at the scrum a won scrum?
In World Rugby’s definitions, yes for the side that did not concede it: a scrum is won where a penalty or free kick goes against the non-feeding team, and lost where the feeding team concedes one. That is also the most likely reason a broadcaster’s figure differs from this page’s.
Why does this page not cover rugby league?
Because rugby league has no lineout at all, restarts a ball into touch with a play-the-ball rather than a scrum, and treats the scrum as a restart rather than a contest — scrums were suspended outright in 2021 on medical advice. There is nothing for a set-piece retention percentage to measure. League’s unit of possession is the set of six tackles.
Related calculators
References
- World Rugby. Game Analysis Definitions, world.rugby/the-game/game-analysis/definitions (read 15 Oct 2026) — the governing body’s own statistical dictionary, in sections headed Scoring, General Play, Set Piece and Sanctions, about 50,000 characters including navigation. It contains NO definition of territory and NO percentage or success rate for a scrum, a lineout or a tackle: it defines the events and leaves every ratio to whoever computes it. Several typographical errors below are the source’s own and are reproduced as found. Quoted: “Own Scrum won — A scrum is won when the ball is channelled to the back of the scrum of the feeding team and normal play resumes”; “Own Scrum lost — A scrum is lost when the ball goes beyond the feet of the opposition’s number 8 and the opposition obtains possession”; “Scrum Collapse On Own Feed”; “Scrum Reset On Own Feed — A reset occurs when the referee asks for the an incomplete scrum to be reformed”; “Own Line-out won — A lineout is won when a team gains possession from the lineout”; “Own lineout lost — A lineout is lost when a team loses possession from the lineout”; “Own Line-out lost due to not straight throw”; “Lineout Contested … the opposition contest in the air”; “Lineout Numbers”; “Quick Throw In”; “Own ruck won”; “Own maul won”; and “Total ball in play is match time minus any time in the match when neither team is in possession of the ball”.
- World Rugby. Laws of the Game — Law 1, The Ground (passport.world.rugby, read 15 Oct 2026). Clause 1.3’s dimensions arrive AS TEXT, in a table, and are quoted on that basis: field of play maximum 100 m, minimum 94 m; width maximum 70 m, minimum 68 m; in-goal maximum 22 m, minimum 6 m. 1.3(e): the perimeter area 5 m “where practicable” and never less than 3.5 m for men’s games or 3.0 m for women’s. 1.4 and 1.5 place the lines — solid halfway and 22 m lines, dash lines 10 m either side of halfway, 5 m from each touchline and try line, 15 m from each touchline — with 1.3(c) and 1.3(d) reducing those spacings on a short or narrow field. 1.6 gives the 0.5 m centre mark, 1.7 limits post padding to 0.5 m, 1.8 requires flag posts of at least 1.2 m and 1.10 places them 2 m outside the touchlines. Length check: about 10,000 characters arrived, Law 1’s own text roughly 2,500 to 3,000, and the goal-posts graphic is NOT readable — so Law 1’s text gives no distance between the posts, no crossbar height and no minimum post height.
- International Rugby League. International Laws of the Game, 2024 edition (cover: “2024 International Laws of the Game”, © 2024 International Rugby League), PDF at rugby-league.com (read 15 Oct 2026). Quoted only where the TEXT says it; the extraction runs to roughly 50,000 characters and is truncated partway through Section 17, and Section 1’s ground plan is an IMAGE, so no field dimension is quoted from this document anywhere on this site. Section 4, Law 1: “The game shall be played by two teams each consisting of not more than thirteen players on the field at any one time.” Section 4, Law 2(a): four nominated replacements and “A maximum of 8 interchanges … from the 17 named players.” Section 7, Law 1: “The game shall normally be of eighty minutes duration.” Section 11, Law 7(a): “A team in possession of the ball shall be allowed five successive play-the-balls”, with a handover when “The team is tackled a sixth time”. Section 11, Law 10(g): defenders other than the marker and acting half “are out of play if they fail to retire ten (10) metres from the point at which the ball is played.” Section 12, Law 3: “No more than six players on each team shall assist in the formation of a scrum.” Section 16, Law 6: the referee may “caution, temporarily suspend for ten minutes, or dismiss the offender.” Section 1, Note 3: “The goal posts are considered to extend indefinitely upwards”; Section 2’s glossary: a corner post “not less than 1.25m. high”.
- National Rugby League. NRL announces rule changes to make game more entertaining, nrl.com, Friday 11 December 2020 (read 15 Oct 2026). The Australian Rugby League Commission, on its innovation committee’s recommendations, confirmed for the 2021 Telstra Premiership that “a two-point field goal will be awarded for teams who kick a field goal from outside the 40-metre line”, field goals from inside the 40 remaining worth one point. The same item records that field goals “were reduced from two points to one in 1971”; that six-again replaces the penalty for 10-metre infringements while referees keep the power to penalise and sin bin; that a ball or carrier into touch restarts with a play-the-ball rather than a scrum; and that “A conversion attempt will not be permitted until the Bunker is satisfied a try has been scored”.
- Yorkshire Evening Post. No scrums in 2021 and ‘two point’ drop goal idea thrown out (read 15 Oct 2026). The RFL Laws Committee “considered, but rejected, two further law changes” taken from the NRL, one of them “awarding two points for drop goals kicked from outside the 40 metre line”; the RFL Board ratified the rejection on 3 February 2021. RFL Chief On-Field Officer Dave Rotheram: “we remain unconvinced by the arguments for introducing a two-point drop goal.” The same item records “no scrums again in rugby league this season”, on medical and scientific advice about Covid-19 risk, with scrums possibly returning “certainly at Betfred Super League level”, and that the committee was “not persuaded of the merits of extending Six Again to cover 10 metre offside infringements”, Six Again having been introduced for the 2020 restart. A press source, and the only account read that records the rejection with its body and date; the RFL’s own operational rules were not reached.