A well-built shooting machine groups more tightly than an archer

The summary today

Well-built machines group very tightly, but there is only one comparison with an archer at the same venue, and nobody has compared them with the best archers on the same equipment. At 30 m a carefully adjusted machine spreads with a standard deviation of 0.9 cm, so that 99.6% of arrows would be expected inside the ten; at 70 m indoors another puts the same arrow a median 1.3 cm from the group centre, with 95% of impacts within 3.5 cm, that is a circle 7 cm across, only slightly wider than the 6.1 cm X; outdoors, on a windless day, a third puts ten arrows out of ten in the 122 mm ten; after a great deal of adjustment, twelve arrows shot at 12 m go into the same hole, and at 25 m the best arrows stay within 13 mm. The only comparison made at the same venue, at 55 m, has an archer spreading 107-108 mm vertically against 34 mm for a robot and 9 mm for its improved version, but it is one archer, of unstated level, shooting different arrows. Two things limit the reading. The first is that consistency comes with construction and with equipment: at 25 m, changing only the nocks takes one arrow's group from 44 to 27 mm; a prototype robot with a training bow stops at a 16 cm circle at 18 m, and a 24 kg machine vibrated so much that it had to be rebuilt at 114. The second is that top archers are already very consistent in launch speed, one or two kilometres per hour from one arrow to the next, so the machine's advantage lies in the rest of the shot. Many tests agree on the machine and there is a single direct comparison, with one archer: that is why the status is "Reported", and the claim says nothing about the best archers.

Also phrased as: "the machine groups better than any archer"; "shooting machine group size"; "the spread is all down to the archer"; "shooting robot accuracy"; "the machine groups better than the best archer"

Evidence

• 1990
  For Equipment tests Published later

  A mechanical release machine with a recurve, shots at 30 m: standard deviation of accuracy 0.9 cm, so that 99.6% of arrows would be expected inside the ten, with a 4 cm radius. The author writes that the result beats that of the best competitors in the world, but the paper contains no archer data to compare it with.

  Experimental and theoretical research in archery · Roman Pekalski

• 2009
  For Equipment tests Published later

  An indoor shooting machine built on a single-axis robot (600 mm travel, repeatability ± 0.01 mm) with a mechanical release and Easton A/C/E 470 arrows preselected with a test at 18 m: the groups tighten to the point of one arrow going into another. The figures show the targets, without a numerical measure of spread and without archers.

  Performance analysis based on an emulated archery machine · Kuo-Bin Lin, Kun-Shu Huang, Chi-Kuang Hwang, Chia-Wen Wu

• 2011
  Context Equipment tests Published later

  A 60.6 lb compound on a shooting machine, four shots measured with a reference chronograph: 82.67, 83.05, 81.97 and 82.61 m/s, a mean of 82.58 with a standard deviation of 0.45 m/s, about 0.5%. It measures the consistency of the launch, not the group.

  A miniaturised arrow ballistic measurement system · John Barton, Jan Vcelak, Javier Torres-Sanchez, Brendan O'Flynn, Cian O'Mathuna, Robert V. Donahoe

• 2011
  Context Equipment tests Published later

  A compound on a shooting machine photographed with a timed flash: the flex amplitude and the lateral position of the arrow relative to the rest repeat from shot to shot within the limit of the camera, with a resolution of about 0.2 mm. Here too what is measured is the consistency of the launch, not the group on the target.

  The Behaviour of An Arrow Shot from a Compound Archery Bow · J L Park

• 2011
  For Equipment tests Published later

  A compound on a shooting machine, repeatability tests before the shots in the wind: twelve arrows shot in succession at 12 m go into the same hole with a maximum error of 1 mm, at 35 m without wind the group's standard deviation stays under 10 mm for both arrow models, and at 70 m without wind the author writes that a perfect score on the target face for that distance is easily obtained. He adds that getting there took a great deal of adjustment, and that casual use of the machine would not deliver it. No archers in the study.

  Minimizing wind drift of an arrow · J L Park

• 2012
  Context Archers Published later

  Three recurve archers from the Malaysian national squad clocked by radar: mean launch speed is 197.9 ± 1.0, 219.4 ± 1.8 and 220.3 ± 0.9 km/h, varying by one or two kilometres per hour from one arrow to the next, 0.4 to 0.8%. There is no machine in the study, but the variability is close to the one measured on a machine in 2011.

  Influence of Muscle Activity on Shooting Performance in Archery: Preliminary Findings · Edin Suwarganda, Ruhil Razali, Barry Wilson, Ahmad Pharmy

• 2017
  For Equipment tests Published later

  A Hoyt compound on a Hooter Shooter machine bolted to the ground, groups at 25 m: with the right nocks the X7 2512 arrows group within 13 mm, just 3.1 mm more than the shaft diameter, and a single arrow shot several times keeps landing close to the same hole; the machine's aiming error is estimated at ± 5 mm. The same work shows how much the equipment matters, though: changing only the nocks takes the X7 2315 group from 44 to 27 mm, and the X7 2712 group from 32 to 15. No archers in the study.

  Effect of arrow shaft straightness on arrow grouping · James L Park, Patrick J Aitchison, Adam J Bielby, Vincent Bleakley, Trent P Carberry, Richard M Ellis, Richard D Kerner, Andrew D MacDonald, Danie Oosthuizen, Scott B Pankhurst, Konstantinos Psarakis

• 2019
  Context Equipment tests Published later

  A prototype robot with a training bow, ten shots with the same arrow at 18 m: all within a circle 160 mm across, with a residual spread the authors put down to wind horizontally and, vertically, to a nocking point wider than the nock. A machine on its own does not guarantee a tight group.

  Statics Investigation about Archery Robot in Drawing a Bow · Takuto Nakamura, Yogo Takada, Hitoshi Watanabe

• 2020
  For Equipment tests Published later

  A 114 kg machine with a 40 lb Yamaha recurve, release triggered by the clicker's sound signal, shots at 70 m on a windless day: ten arrows out of ten in the 122 mm ten.

  Development of an Archery Robot for the Selection of Arrows · Masashi Ohara, Naoki Kawasaki, Jun Nakahama, Yogo Takada, Hitoshi Watanabe

• 2020
  Context Equipment tests Published later

  The first version of the same machine weighed 24.1 kg, vibrated as the string was drawn and lost precision; the second was designed to exceed 100 kg and reached 114.4, about 4.7 times as much, with a motor in place of the crank and steel tubing in place of aluminium.

  Development of an Archery Robot for the Selection of Arrows · Masashi Ohara, Naoki Kawasaki, Jun Nakahama, Yogo Takada, Hitoshi Watanabe

• 2022
  For Equipment tests Published later

  Shots at 55 m in a sports hall, analysed with cameras at 3,000 frames per second: one archer, 36 A/C/E arrows, spreads 107 and 108 mm vertically (standard deviation) with a launch speed varying by 0.34-0.40 m/s; the robot, with X10 arrows, 34 mm and 0.13 m/s, and its improved version 9 mm and 0.019 m/s, enough, according to the authors, to stay inside the X at 70 m indoors. The archer's level is not given and the arrows are different.

  Automatic image analysis of an archery arrow in free flight using high-speed video cameras · Riku Murakami, Hiroya Mamori, Takeshi Miyazaki, Naoya Takahashi

• 2025
  For Equipment tests Published later

  A shooting machine with a recurve at 70 m indoors: the same arrow shot 30 times lands a median 1.3 cm from the group centre (95% CI 0.8-2.1), with 95% of impacts within 3.5 cm; over five sessions each of the 59 arrows of the same model varies by about 2.2 cm horizontally and 2.0 vertically. No archers in the study.

  Improving the arrow selection process in archery: the stiffness variation pattern matters · A. Kuch, P. Laguillaumie, F. Durand, J.-F. Debril, T. Monnet

Status history

1. 1990 Reported A well-adjusted mechanical release machine at 30 m spreads with a standard deviation of 0.9 cm: 99.6% of arrows would be expected inside the ten, and the author writes that this beats the best competitors in the world. It is a test on equipment, direct for this domain, but a single one and without any group of archers measured under the same conditions: reported.
2. 2009 Reported A second machine, built on a single-axis robot repeatable to a hundredth of a millimetre, with preselected arrows, tightens the groups until one arrow goes into another. There are now two tests in favour, but neither puts an archer under the same conditions: the status stays reported.
3. 2011 Reported Three bench tests measure where the consistency comes from and how far it goes. On a compound in a machine the launch speed varies by about half a percentage point over four shots, and the arrow's flex and lateral position repeat from shot to shot within the camera's resolution; in a third paper twelve arrows shot at 12 m go into the same hole, at 35 m the group has a standard deviation under 10 mm and at 70 m, without wind, a perfect score comes easily, but only after a great deal of adjustment. The tests in favour of a tight group are growing, and none puts an archer alongside: the status remains reported.
4. 2012 Reported The first measurement on high-level archers narrows the field: in three archers from the Malaysian national squad launch speed varies by only one or two kilometres per hour from one arrow to the next, 0.4 to 0.8%, not far from the 2011 machine. On launch consistency the best archers are not far behind, so the machine's advantage has to be sought in the group at distance, where nobody has yet compared the two.
5. 2017 Reported A machine bolted to the ground, at 25 m, puts the best arrows in a 13 mm group, only slightly wider than the shaft, but the same work shows that changing only the nocks takes another arrow's group from 44 to 27 mm: with the archer removed, the group still depends on the equipment. It is one more test in favour of the machine, again with no archer under the same conditions, and the status remains reported.
6. 2019 Reported A prototype robot with a training bow shoots the same arrow ten times at 18 m and keeps it inside a 16 cm circle every time, and the authors put the spread down to wind and a nocking point wider than the nock. It is a reminder that consistency depends on how the machine is built: the status does not move.
7. 2020 Reported A machine taken up to 114 kg, precisely because the first one, at 24 kg, vibrated and lost precision, puts ten arrows out of ten in the ten at 70 m on a windless day. The tests in agreement are growing, but there is still no direct comparison with a group of archers: it stays reported.
8. 2022 Reported The first comparison at the same venue arrives: at 55 m an archer spreads 107-108 mm vertically against 34 mm for a robot and 9 mm for its improved version, with a much less consistent launch speed. It points the way of the claim, but there is a single archer, of unstated level, shooting different arrows from the robot's: the status stays reported.
9. 2025 Reported A machine's repeatability is measured at 70 m: the same arrow shot thirty times lands a median 1.3 cm from the group centre, with 95% of impacts within 3.5 cm, a circle only slightly wider than the X. The measurement is at the Olympic distance, but still with no archers alongside: many tests agree on the machine, there is a single direct comparison with an archer, and the status stays reported.

Related

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• Does better equipment put points on the scorecard? What shooting machines and archers showShooting machines, archers handed a bow that is not theirs and blind ratings: what the studies say about how much equipment counts towards your score.
• Choosing and matching competition arrowsWhich spine to choose and how alike the arrows in a dozen are: charts, weight, the stiff side of the shaft, straightness and nocks, as studies measure them.
• When to retire an arrow, and why a shaft snaps on releaseWhich knocks damage an arrow, why a shaft snaps on release, and what the tests say about straightness, wear and defective arrows.

Research lines

• 29 studiesThe archer's paradox in research: from 1987 to today
• 32 studiesArrow aerodynamics: drag, boundary layer, vanes

Other claims in this domain

• CorroboratedAlong its flight the arrow loses an appreciable part of its launch speed12 studiesStatus since 2011
• CorroboratedAs it leaves the bow, the arrow flexes and snakes around the riser instead of leaving straight19 studies · 47 archers measuredStatus since 2012
• ReportedA camera-based scoring system misreads some arrows: the ones barely sticking out and the ones that shift the target face7 studies · 2 archers measuredStatus since 2017
• ReportedA chest band with fibre optic sensors measures breathing and mean heart rate with small errors, and an archer can wear it while shooting2 studiesStatus since 2019
• ReportedA compound bow stores between 70 and 100 joules and sheds about two thirds of the force at full draw4 studiesStatus since 2015

See all claims on equipment and tuning