Conversion Points Added

This past weekend I posted a simple table of individual conversion stats gathered from World Rugby. It was a complete list along with each kicker’s conversion success rate. World Rugby keeps tabs on the leaders in total conversions, but we can’t tell who are actually the best kickers since the quantity and difficulty of the attempts are not equal.

Fortunately, I track the width of each conversion attempt. With this, I ran a logistic regression for success rate dependent on the conversion width. This regression allows us to plug in the width of a conversion to get the average success rate at that width. For example, a dead-center conversion is expected to be made around 97% of the time while a conversion from the touchline is only successful about 18% of the time.

In this fashion I calculated how many points each kicker’s profile of kicks is worth if averaged across all kickers. For example, let’s say a kicker had two attempts, one from dead-center and one from the touchline. Using the percentages from above, the average (across all kickers) would earn .97 x 2 = 1.94 points on the centered conversion and .18 x 2 = .36 points on the wide kick for a total of 2.3 points.

Again, this is on average. So some kickers do better than others. If Kicker A made both kicks to score 4 points, he actually scored 1.7 more points than the average. And if Kicker B missed both, his 0 points are 2.3 points less than the average. Using this method I tallied how many points above or below the average each kicker has added through all of his attempts.

Player Team Cons Attempts % Pts+ Pts+ per Att
Gaston Revol ARG 59 88 67.0 % 17.8 0.20
Scott Wight SCO 95 126 75.4 % 14.8 0.12
Ethan Davies WAL 82 113 72.6 % 12.5 0.11
Terry Bouhraoua FRA 43 57 75.4 % 11.3 0.20
James Stannard AUS 74 117 63.2 % 10.2 0.09
Rocky Khan NZL 40 53 75.5 % 9.6 0.18
Tom Mitchell ENG 79 114 69.3 % 9.5 0.08
Katsuyuki Sakai JPN 45 62 72.6 % 7.5 0.12
Nathan Hirayama CAN 71 105 67.6 % 6.4 0.06
Branco Du Preez RSA 67 108 62.0 % 3.7 0.03
Beaudein Waaka NZL 30 46 65.2 % 3.2 0.07
Isaac Te Tamaki NZL 9 12 75.0 % 3.1 0.26
Javier Rojas ARG 23 36 63.9 % 2.2 0.06
Joe Webber NZL 3 5 60.0 % 2.1 0.42
Tila Mealoi SAM 72 108 66.7 % 2.1 0.02
Osea Kolinisau FIJ 74 104 71.2 % 2.1 0.02
Folau Niua USA 4 10 40.0 % 2.1 0.21
Kevin Kermundu UGA 3 3 100.0 % 2.0 0.67
Vatemo Ravouvou FIJ 39 62 62.9 % 2.0 0.03
Tom Lucas AUS 16 21 76.2 % 1.8 0.09
Amenoni Nasilasila FIJ 11 15 73.3 % 1.7 0.11
Lloyd Evans WAL 1 2 50.0 % 1.6 0.80
Billy McBryde WAL 10 12 83.3 % 1.3 0.11
Rosko Specman RSA 2 2 100.0 % 1.1 0.55
Igor Genua ESP 4 5 80.0 % 1.1 0.22
Han Gumin KOR 2 2 100.0 % 1.0 0.50
Sam Caslick AUS 4 6 66.7 % 1.0 0.17
Alivereti Veitokani FIJ 6 10 60.0 % 1.0 0.10
Alexis Palisson FRA 0 1 0.0 % 1.0 1.00
Stephen Parez FRA 10 14 71.4 % 0.8 0.06
Leon Ellison JPN 12 16 75.0 % 0.7 0.04
Jonathan Ruru NZL 2 5 40.0 % 0.7 0.14
George Horne SCO 1 1 100.0 % 0.5 0.50
Luke Treharne WAL 5 8 62.5 % 0.5 0.06
Jean Pascal Barraque FRA 21 31 67.7 % 0.5 0.02
Domingo Miotti ARG 3 5 60.0 % 0.4 0.08
Madison Hughes USA 92 142 64.8 % 0.4 0.00
Selvyn Davids RSA 1 1 100.0 % 0.4 0.40
Vladimir Ostroushko RUS 1 2 50.0 % 0.4 0.20
Will Edwards ENG 5 5 100.0 % 0.3 0.06
German Klubus ARG 1 1 100.0 % 0.2 0.20
Pablo Fontes ESP 2 2 100.0 % 0.1 0.05
Julien Candelon FRA 2 2 100.0 % 0.1 0.05
Alatasi Tupou SAM 9 13 69.2 % 0.1 0.01
Mikhail Kudinov RUS 1 1 100.0 % 0.1 0.10
Emosi Mulevoro FIJ 1 1 100.0 % 0.1 0.10
Jamie Henry JPN 1 1 100.0 % 0.1 0.10
Ilya Babaev RUS 1 1 100.0 % 0.1 0.10
Tomasi Alosio SAM 1 1 100.0 % 0.1 0.10
Nick McLennan SCO 1 1 100.0 % 0.1 0.10
Laaloi Leilual SAM 1 1 100.0 % 0.1 0.10
Masahiro Nakano JPN 0 1 0.0 % 0.1 0.10
Patrick Stehlin JPN 1 1 100.0 % 0.1 0.10
Andrew Durutalo USA 1 1 100.0 % 0.1 0.10
Josua Vici FIJ 1 1 100.0 % 0.1 0.10
James Johnstone SCO 1 1 100.0 % 0.1 0.10
Dewald Human RSA 1 1 100.0 % 0.1 0.10
Stephen Tomasin USA 17 23 73.9 % 0.1 0.00
Emmanuel Guise PNG 2 3 66.7 % -0.1 -0.03
Joaquin Riera ARG 4 10 40.0 % -0.1 -0.01
Kosuke Hashino JPN 6 9 66.7 % -0.3 -0.03
John Porch AUS 2 3 66.7 % -0.3 -0.10
Justin Geduld RSA 27 45 60.0 % -0.3 -0.01
Gavin Lowe SCO 10 16 62.5 % -0.3 -0.02
Nicolas Menendez ARG 0 1 0.0 % -0.4 -0.40
Phil Burgess ENG 0 1 0.0 % -0.4 -0.40
Eugene Tokavai PNG 0 1 0.0 % -0.5 -0.50
Gregor Hunter SCO 2 3 66.7 % -0.5 -0.17
Harry Jones CAN 0 1 0.0 % -0.6 -0.60
Brandon Quinn AUS 0 1 0.0 % -0.6 -0.60
Blair Kinghorn SCO 1 2 50.0 % -0.7 -0.35
Yoshiaki Tsurugasaki JPN 0 1 0.0 % -0.7 -0.70
Scott Curry NZL 0 1 0.0 % -0.7 -0.70
Vincent Inigo FRA 1 2 50.0 % -0.7 -0.35
Pierre Popelin FRA 0 1 0.0 % -0.8 -0.80
Francisco Urroz CHL 0 1 0.0 % -0.8 -0.80
Cecil Afrika RSA 30 46 65.2 % -0.8 -0.02
Liam McNamara AUS 0 2 0.0 % -0.9 -0.45
Matias Ferro ARG 0 1 0.0 % -0.9 -0.90
Martin Iosefo USA 0 1 0.0 % -0.9 -0.90
Tate McDermott AUS 1 2 50.0 % -1.0 -0.50
Kitione Taliga FIJ 8 10 80.0 % -1.2 -0.12
Jamie Hood HKG 4 8 50.0 % -1.2 -0.15
Fernando Luna ARG 2 3 66.7 % -1.2 -0.40
Lee Jaebok KOR 0 1 0.0 % -1.3 -1.30
Morgan Williams WAL 1 3 33.3 % -1.8 -0.60
Mike Fuailefau CAN 3 5 60.0 % -1.9 -0.38
Tim Mikkelson NZL 1 4 25.0 % -2.0 -0.50
Yury Gostyuzhev RUS 1 4 25.0 % -2.1 -0.52
Jeremy Aicardi FRA 11 15 73.3 % -2.3 -0.15
Mike Teo USA 2 6 33.3 % -2.5 -0.42
Brian Tanga KEN 8 14 57.1 % -2.6 -0.19
Philip Wokorach UGA 11 19 57.9 % -2.6 -0.14
Ruhan Nel RSA 1 3 33.3 % -2.7 -0.90
Oliver Lindsay-Hague ENG 0 2 0.0 % -2.7 -1.35
Arthur Clement PNG 5 8 62.5 % -2.9 -0.36
Waisea Nacuqu FIJ 7 11 63.6 % -3.2 -0.29
Lautaro Bazan Velez ARG 1 5 20.0 % -3.2 -0.64
Roman Roshchin RUS 0 5 0.0 % -3.6 -0.72
Marcelo Torrealba CHL 6 12 50.0 % -3.9 -0.32
Jamie Booth NZL 0 3 0.0 % -3.9 -1.30
Eden Agero KEN 27 39 69.2 % -4.1 -0.11
German Davydov RUS 4 10 40.0 % -4.2 -0.42
Daniel Bibby ENG 25 41 61.0 % -5.0 -0.12
Dmitry Perov RUS 3 10 30.0 % -5.4 -0.54
Lugonzo Augustine Ligamy KEN 16 25 64.0 % -6.6 -0.26
Pat Kay CAN 18 30 60.0 % -8.4 -0.28
Vilimoni Koroi NZL 19 40 47.5 % -9.7 -0.24
Samuel Oliech KEN 33 53 62.3 % -14.2 -0.27
Dmitry Sukhin RUS 24 52 46.2 % -16.4 -0.32

So while Scott Wight has the best success rate, Gaston Revol has added the most points above the average for his profile of kicks. This is due to Revol’s more difficult set of kicks (average width of ~20m compared to Wight’s ~14m). If given Wight’s set of conversion attempts, Revol would likely have a higher success rate.

The last column shows our points added on a per attempt basis. This helps us compare kickers who may have significantly different quantities of kicks. Terry Bouhraoua has many fewer attempts due to injury, but his points added per attempt is as good as Revol’s.

It should be noted that both of these metrics are influenced by the profile of kicks. If a kicker was given 100 kicks from straight in front of the posts and made them all, they could only add .06 points per attempt for a total of 6 points added. But all of the regular kickers above avoid this sort of extreme kicking profile.

Application
While not perfect, I think this method does a better job comparing kickers than success rate alone. Also, quantifying each kicker’s ability in terms of points helps frame their influence on an individual match or tournament, where one extra touch-line conversion can greatly influence the outcome.

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