An expert archer repeats the arrow's speed from shot to shot almost as closely as a shooting machine

The summary today

The measurements that exist all point the same way, but they are few and small. In seven elite German archers, over thirty arrows at eighteen metres, the arrow's mean speed varies from shot to shot by between 0.23 and 0.58 per cent, less than a tenth of the variation in the time between the clicker dropping and the release. In the laboratory an expert archer from the Japanese national team repeats launch speed within 0.6 per cent at 58 metres a second, against 0.3 per cent for the compressed-air launcher used in the same study; a compound shot by a machine and measured with the NIST reference chronograph varies by about half a percentage point. So the expert archer is in the same order of magnitude as the machine, but not at the same level: in the only direct comparison, which concerns a single archer, her spread is twice as large. In the German sample, moreover, how much speed varies does not explain the differences in score between archers, which follow the regularity of the release.

Also phrased as: "arrow speed consistency"; "shot-to-shot speed variation"; "the archer as a machine"; "shot repeatability"; "constant arrow speed"

Evidence

• 2005
  Context Archers Published later

  Twenty elite Turkish archers, twelve arrows at 70 m in two sessions a week apart: mean speed 184.19 ± 4.54 km/h against 183.71 ± 4.40, ICC 0.990, mean difference 0.481 km/h (p = 0.002). It shows that each archer's mean is stable from one day to the next, not how much it varies from one arrow to the next.

  Reliability and validity testing of an archery chronometer · Hayri Ertan, Behzat B. Kentel, S. Turgut Tümer, Feza Korkusuz

• 2011
  Context Equipment tests Published later

  A 60.6 lb compound at 29 inches of draw, 24.753 g arrow, shot by a Spot-Hogg machine: the NIST reference chronograph reads 82.67, 83.05, 81.97 and 82.61 m/s over four shots, a mean of 82.575 with a standard deviation of 0.448 m/s, about 0.5%. It is the machine's yardstick, with a different bow from the archers'.

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

• 2012
  For Archers Published later

  Seven elite archers from the German junior and senior squads, thirty arrows at 18 m indoors, timings taken with a microphone, from which the mean speed between release and impact is derived: its coefficient of variation ranges from 0.23% to 0.58% across the seven archers, against 3.94-7.25% for the time between the clicker dropping and the release, more than ten times as much.

  Evaluation of arrow release in highly skilled archers using an acoustic measurement system · Mario Heller

• 2012
  Context Archers Published later

  In the regression on mean score, neither mean speed nor its variation explains the differences between archers: only the variation in release time counts, accounting on its own for 66% of the variability in score. With seven archers the result should be taken with caution, as the authors say.

  Evaluation of arrow release in highly skilled archers using an acoustic measurement system · Mario Heller

• 2012
  For Archers Published later

  Indoor flight tests with A/C/E arrows: an expert archer from the Japanese national team, recurve bow, 36 shots, repeats launch speed within 0.6% at 58 m/s. The compressed-air launcher in the same study stays within 0.3% up to 62 m/s and rises to 0.8% between 62 and 75 m/s. For the authors the machine's accuracy is comparable to that of expert national-team archers.

  Aerodynamic properties of an archery arrow · Takeshi Miyazaki, Keita Mukaiyama, Yuta Komori, Kyouhei Okawa, Satoshi Taguchi, Hiroki Sugiura

• 2013
  Context Archers Published later

  It returns to the same expert archer's 36 shots, A/C/E arrow at 58 m/s: the drag coefficient derived from them is about 2.65 with a relative error below 3%, which according to the authors reflects both the accuracy of the measurement and the archer's high repeatability. The 3% refers to the drag coefficient, not to speed, and the data are those of the 2012 study.

  Free Flight and Wind Tunnel Measurements of the Drag Exerted on an Archery Arrow · K. Okawa, Y. Komori, T. Miyazaki, S. Taguchi, H. Sugiura

Status history

1. 2005 Not studied The first figure that comes close to the question is from a field chronometer tested on twenty elite Turkish archers: a week apart, the mean speed of their arrows at seventy metres repeats almost exactly, with an intraclass correlation coefficient of 0.990. That is the mean of twelve arrows compared across two days, though, not the variation from shot to shot, and there is no machine to compare it with: not studied.
2. 2011 Not studied The yardstick arrives, but not the archer. A compound shot by a machine and measured with the NIST reference chronograph launches at 82.58 metres a second on average over four shots, with a standard deviation of 0.45, about half a percentage point. On an archer's consistency there is still nothing: not studied.
3. 2012 Reported Two measurements arrive in the same year. In seven elite German archers the arrow's mean speed varies by between 0.23 and 0.58 per cent from shot to shot, less than a tenth of the variation in the time between the clicker dropping and the release. In the laboratory an archer from the Japanese national team repeats launch speed within 0.6 per cent, against 0.3 for the compressed-air launcher. They point the same way, but the German sample is small and has no machine alongside it, and the only direct comparison concerns a single archer and finds her spread twice the machine's: reported.

Related

Related articles

• 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.
• How fast an arrow flies: the metres per second, what decides them and how much they matter on the targetHow many metres a second recurve and compound arrows fly, what decides launch speed, and how much speed matters on the target and for the score.

Research lines

• 32 studiesArrow aerodynamics: drag, boundary layer, vanes
• 102 studiesFrom the total on the scorecard to the arrow's coordinates

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