About fifteen thousandths of a second pass between the start of the release and the arrow leaving the string

8 studies · 38 archers measured

ForContextAgainst198019902000201020202012, for, n = 162012, context, n = 161994, context, n = 122012, context, n = 71987, against, n = 12009, context, n = 12009, context, n = 11981, for2009, for
Each circle is a study: its position gives the year, its row whether it is for, against or context, its size how many participants it measured. Light circles are studies on other populations or without archers.

From the start of the release to the arrow leaving the string, study by study

Each row is a study or a group: the dot is the mean or the figure the study gives, the whiskers the standard deviation where the study reports it, the vertical line the claim's figure of about fifteen milliseconds. For Park and Logan 2012 the numbers are those in Table 1, with time counted from the start of the release as seen on video; in the text the same article writes 14.7 ms with a standard deviation of 1.2. Park 2009 is a calculation on a compound bow, not a measurement on an archer: photographs on the same bow put the separation between 17.0 and 17.25 ms. Marlow 1981 is also a calculation, on a longbow with an elastic string and typical values chosen by the author: 16.1 ms, from Table II. Leonardi et al. 1987 follow a single Italian national-team archer with an accelerometer and count from when the limbs begin to return, an instant taken from the clicker and the string used as switches: it may not coincide with Park and Logan's, and the difference between the two figures may lie entirely there. Squadrone and Rodano 1994 write that the release lasts about 0.03 seconds, three frames at 100 per second, without saying where the figure comes from. Huang et al. 2009 assign to the release, after looking at the data, the last 60 frames at 1,200 per second: the first 40, about 33 ms, to the bow's movement as the string goes, the last 20 to the arrow already free. The dot sits at those roughly 33 ms, which are a chosen window and not a measurement of the separation. Left out are Horsak 2009, which measures finger movement, and Heller 2012, which measures the time between clicker and shot, before the release. Data from: Park and Logan 2012, Park 2009, Marlow 1981, Leonardi et al. 1987, Squadrone and Rodano 1994 and Huang et al. 2009.
The numbers in the figure
Study or groupValue (milliseconds)IntervalnStance
Park and Logan 2012, all sixteen14.6± 1.3 (mean ± standard deviation)16for
Park and Logan 2012, men14± 1.3 (mean ± standard deviation)8for
Park and Logan 2012, women15.2± 1 (mean ± standard deviation)8for
Park 2009, compound model17.5for
Marlow 1981, longbow model16.1for
Leonardi et al. 1987, accelerometer≈ 301against
Squadrone and Rodano 1994, figure quoted≈ 30context
Huang et al. 2009, chosen window≈ 331context

The most precise measurement is a single one, and it is clear. In 2011, at the London Olympic test event, a camera running at 4,000 frames per second filmed sixteen world-class recurve archers at 70 m: the string stays on the fingers for 1.9 thousandths of a second on average, the nock reaches its point closest to the body at 5.4, the arrow straightens again at 8.6 and leaves the string at 14.6, with standard deviations between 0.4 and 1.3 thousandths; between men and women, with draw weights from 146 to 227 newtons and arrows from 660 to 775 millimetres, the differences stay below one and a half thousandths. Two models of the bow calculate similar times, 16.1 thousandths for a longbow in 1981 and 17.5 for a compound in 2009, where photographs on the same bow put the separation between 17.0 and 17.25. The oldest measurement on an archer, however, gives twice as much: in 1987 an Italian national-team archer, with an accelerometer on the bow, took thirty thousandths from the start of the limbs' return to separation, with a time zero taken from the clicker and the string used as switches, and in 1994 another Italian group writes the same figure, three frames at a hundred per second, without measuring it. The two measurements may not start from the same instant, and the difference may lie entirely in the definition: until someone compares them on the same shots the precise figure remains contested, while the order of magnitude, the hundredth of a second, is the same for everyone. By contrast, the time between the clicker dropping and the shot, measured in seven German national-squad archers, runs from 144 to 176 thousandths, ten times as long.

Also phrased as: "how long the release lasts"; "the release takes an instant"; "arrow exit time"; "the arrow leaves the string in milliseconds"; "nothing can be corrected during the release"; "time the arrow spends on the string"; "duration of the power stroke"; "milliseconds of the release"

In practice

It is said that the release is too fast to be corrected while it happens, that only a few hundredths of a second pass between the release and the arrow leaving, and that what matters is decided before it, in the hold and the draw.

Evidence

  • 1981
    For Model Published later

    An analytical model of a longbow with an elastic string, with no archer involved: with a 25-gram arrow, a 7-gram string and a bow of 39 pounds at 28 inches, the arrow leaves the string 16.1 ms after the release, 1.94 cm beyond the string's rest position, at 52.8 m/s against 56.0 for the rigid-string model. It is a calculation on typical values chosen by the author, not a measurement, and the bow modelled is a longbow.

    Bow and arrow dynamics · W. C. Marlow

  • 1987
    Against Archers Published later

    One top archer from the Italian national team with an Olympic recurve, 15 shots in each of 3 stabiliser set-ups, a lateral accelerometer on the bow sampled at 2,500 Hz, with the clicker and the string used as switches: from the start of the limbs' return to the arrow leaving the string about 0.030 seconds pass, in three phases ending at 0.022 s (the arrow presses on the button), 0.026 s (the button springs back and the arrow no longer touches the riser) and 0.030 s (the arrow is still on the string). It is twice the 14.6 ms measured on camera in 2012, so it goes against the claim's figure, but on a single archer and with a time zero taken from the switches, which may not coincide with the start of the release.

    Reduction of Lateral Bow Displacement Using Different Torque Flight Compensators and Stabilizers in Archery · L. M. Leonardi, C. Gallozzi, A. Pace, A. Dal Monte

  • 1994
    Context Archers Published later

    12 archers from the Italian federation, 20 shots each at 12 m, movement analysis at 100 Hz with electromyography and a force plate: the authors write that the release phase lasts about 0.03 seconds, or 3 frames, to explain why they do not analyse it, without saying where the figure comes from. At that frequency the precision is one hundredth: it is a figure quoted, not a measurement.

    Multifactorial analysis of shooting archery · Roberto Squadrone, R. Rodano

  • 2009
    Context Archers Published later

    An experienced recurve archer from the Austrian B squad, 56 usable shots at 18 m filmed with eight cameras at 500 Hz, split into shots in the centre and shots scoring 8 or less: in one of the two groups the proximal interphalangeal joint of the middle finger reaches a peak angular velocity of 6,923 ± 1,063 degrees per second (5,495 to 8,392) and a minimum of -4,558 ± 443, with no significant difference between the groups. The finger movement curves are shown over a 66 ms window around the peak. It measures the fingers, not the arrow leaving.

    A Kinematic Analysis of Finger Motion in Archery · B. Horsak, M. Heller, A. Baca

  • 2009
    For Model Published later

    A dynamic model of a compound bow and its cams: after the release the arrow spends nearly 60% of its time on the string while covering only the first 20% of the distance from full draw to brace height, and the calculated time on the string is 17.5 ms. Photographs of the arrow on the same bow put the separation between 17.0 and 17.25 ms, measured to 0.25 ms. It is a compound, not a recurve, and the figure describes the bow, not an archer's movement.

    A compound archery bow dynamic model, suggesting modifications to improve accuracy · J L Park

  • 2009
    Context Archers Published later

    1 good-level archer with stable technique, 36 arrows at 30 m, a laser pointer on the bow filmed at 1,200 frames per second: looking at the data, the authors assign the last 60 frames (a twentieth of a second) to the release phase, the first 40 of them, about 33 ms, to the bow's movement while the string goes and the last 20 (a sixtieth) to the arrow, already free, passing the clicker and button. It is a chosen window, not a measurement of the moment of separation.

    Time series analysis during the releasing arrow stage · Kun-Shu Huang, Chi-Kuang Hwang, Kuo-Bin Lin, Chia-Wen Wu

  • 2012
    For Archers Published later

    16 world-class recurve archers (8 men and 8 women), London 2011 Olympic test event, 70 m, camera at 4,000 frames per second: from the start of the release the string stays on the fingers for 1.9 ms (SD 0.4; range 1.50 to 2.25), the nock reaches its point closest to the body at 5.4 ms (SD 0.5), contact with the button ends between 5.5 and 8 ms, the arrow is straight at 8.6 ms (SD 1.1), reaches its maximum opposite flex at 12.4 ms (SD 1.1) and leaves the string at 14.6 ms (SD 1.3). In none of the 16 does the bow move sideways or rotate before the arrow has left the string.

    High-speed video analysis of arrow behaviour during the power stroke of a recurve archery bow · James L Park, Oliver Logan

  • 2012
    Context Archers Published later

    In the same archers the men are slightly faster than the women at every stage, but only just, by 1.2 thousandths at most: string off the fingers 1.7 against 2.1 ms, arrow straight 8.4 against 8.9, nock off the string 14.0 against 15.2. Draw weights run from 204 to 227 N in the men and from 146 to 203 N in the women, arrows from 699 to 775 mm and from 660 to 711 mm, yet the standard deviations of the times stay between 0.3 and 1.3 ms.

    High-speed video analysis of arrow behaviour during the power stroke of a recurve archery bow · James L Park, Oliver Logan

  • 2012
    Context Archers Published later

    7 recurve archers from the German junior and senior national squads, 30 arrows at 18 m recorded with a microphone: the mean time between the clicker dropping and the shot runs from 144.40 to 175.96 ms depending on the archer, with coefficients of variation from 3.94 to 7.25%, and its variability accounts for 66% of the differences in score. It is the time before the release, ten times longer than the time separating the release from the arrow leaving.

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

Status history

  1. 1981 Transferred The first answer comes from a calculation, not a measurement. An analytical model of the longbow with an elastic string has the arrow leaving the string 16.1 thousandths after the release, just beyond the string's rest position, while limbs and string are still moving. No archer was filmed and the parameters are typical values chosen by the author: the claim rests on a model, and a model leaves the status at transferred.
  2. 1987 Contradicted The first measurement on an archer comes from a laboratory in Rome: a top Italian national-team archer, an accelerometer on the bow sampled at 2,500 hertz, and thirty thousandths of a second from the start of the limbs' return to the arrow separating, in three phases ending at 22, 26 and 30 thousandths. It is twice the claim's figure, with a time zero taken from the clicker and the string used as switches: a single study on archers, and it goes against, so contradicted.
  3. 2009 Contradicted As early as 1994 another Italian group had written the same thirty-thousandths figure, three frames at a hundred per second, but without measuring it. In 2009 a dynamic model of the compound calculates 17.5 thousandths of arrow on the string, and photographs on the same bow put the separation between 17.0 and 17.25: a second calculation close to the claim's figure, checked on the bow. The same year one archer filmed at 500 Hz gives the scale of finger movement, and another at 1,200 frames a release window chosen by looking at the data. Neither measures the arrow separating, so on archers the only measurement is still the 1987 one, which goes against: contradicted.
  4. 2012 Contested The first high-speed measurement of the sequence comes out. Sixteen world-class recurve archers, filmed at 4,000 frames per second at the London Olympic test event: the string stays on the fingers for 1.9 thousandths, the arrow is straight at 8.6 and leaves the string at 14.6, with standard deviations no larger than 1.3 thousandths. That is half the thirty thousandths of 1987, measured on a single archer and perhaps from a different instant. The same year an acoustic system measures, in seven German national-squad archers, the time between clicker and shot, from 144 to 176 thousandths, which gives the contrast but does not touch the question. One measurement in favour and one against: contested.

Related

Related articles

Research lines

Cite
APA

Campagna, M. (2026). About fifteen thousandths of a second pass between the start of the release and the arrow leaving the string (Version 3). In Evidence Registry. Retrieved 16 October 2026, from https://matteocampagna.com/en/registry/technique/release-to-arrow-separation-time

BibTeX
@misc{campagna2026_rilasciopochimillisecondi,
  author = {Campagna, Matteo},
  title = {About fifteen thousandths of a second pass between the start of the release and the arrow leaving the string},
  year = {2026},
  howpublished = {Evidence Registry, matteocampagna.com},
  url = {https://matteocampagna.com/en/registry/technique/release-to-arrow-separation-time},
  note = {Version 3; accessed 2026-10-16}
}

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