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  • nmzoo
    replied
    And to follow up on 26mi235's comments (sorry, I can't help myself), positioning of the starter is much more important than most people think.

    For the 100m, when a starter stands about 5 meters in front of lane 1 on the "grass", a common position, it takes more than twice as long for the sound of the gun to reach lane 8 as it does to reach lane 1 (approx 0.032 sec vs 0.015 sec, not much but races are won and lost by less time).

    Starts of staggered lane races are even much worse at times. A common position for starters in these instances is to assume a position on the track near the athlete in lane 8, sometimes even beyond the stagger in lane 8 such that they can see all runners in the race. In the 200m this causes the sound of the gun to take as much as 4 times as long to reach lane 1 as to reach lane 8 (approx 0.015 sec vs 0.056 sec). In the 400m, for a similar positioning, the time difference can be as much as 0.095 sec. And in races staggered for 3 turns the times difference can be 0.135 sec, more than a meter in fairly fast competitions. For this reason, under these circumstances, a runner would be better off in an "outside lane" as opposed to an inside, not to mention that the runner has less of a turn to run and the turn is more "gentle". These facts can make as much as a 0.25 sec difference in the 200m and 0.40 sec. in the 400m, to a runner in lane 8, as opposed to lane 1. And, with a 3 turn stagger, because of running 3 "gentler" turns, it is worth almost 0.5 sec. to a team leading off in lane 7-8.

    The best compromise for the positioning of a starter for staggered races is about 20 meters back on the infield (25 meters for a 3 turn stagger) in line with the stagger in lane 4 or 5. This gives a lag time of the sound of about 0.07 sec, but it is very much the same for all runners. I have seen this used a few times, but it is not common.

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  • Riff80
    replied
    As far as how school's list the top 10. Many schools will just have two list, one FAT and one HT.

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  • 26mi235
    replied
    to carry on nmzoo's comments, think about the 100m, where the timer is ~100m from the gun. Since sound travels at 300m/second, it is a third of a second to get to the finish. Thus, relying on the sound adds a big lag (unless a mic picks up the sound and it is re-transmitted much closer to the timer...), and the smoke is the signal, and it is a bit slower to recognize. That the sound issue is important is demonstrated on a couple of threads (started by gh) about the differential reaction times when the start (of the 200?) was done with the gun instead of the signals at the back of blocks (Atlanta, 96? and others).

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  • nmzoo
    replied
    As has been stated, the accepted procedure is to add 0.24 sec (for races shorter than 400m) and 0.14 sec. (seems to me it would be the same) for races longer, to correlate hand times to FAT times. This is supposed to be done AFTER rounding the hand times to the next higher 0.1 sec. Even though hand times are supposed to be reported only to the next higher 0.1 sec, this convention is almost never followed using hand timing (especially HS). In fact, some states require hand times be reported to 0.01 sec. for qualifying purposes.

    Hand timing errors occur principally at the start where the timers are reacting to a stimulus the same as the runners. Since the "conventional wisdom" has put a reaction time of less than 0.1 sec as a false start, and since the timing commences at the exact instatnt the gun goes off, timers will have at least this much error in their times compared the the FAT times (assuming the "conventional wisdom" is correct).

    It has been reported somewhere in the past (I just don't remember where), that runners react more quickly to an auditory stimulus than to a visual one. And since timers are usually reacting to a visual stimulus (smoke, fire), their lag time is going top be even greater than the runners (not to mention that their reaction time is probably almost always slower than trained runners anyway). Hence the 0.24 sec accepted difference.

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  • 26mi235
    replied
    Originally posted by dukehjsteve
    in the past, .24 in the 100 ,200, and Hhurdles, .14 in the 2 one lappers.... don't recall the longer stuff.
    Using the lower factors for the events where the start and finish are together works for the timers at the S/F line, but not for those situated elsewhere, where the 0.24 seconds would likely be a more accurate translation, but of course such times would not be used for the school record board.

    My local newspaper and my old one (LA Times) have typically listed the marks in chronological order even though a 'simple' reading would make them look out of order. For instance this would be a correct ordering because the converted times are in order [marks]

    10.55 [10.55]
    10.4 [10.64]
    10.5 [10.74]
    10.77 [10.77]
    10.6 [10.84]

    Of course, there is the issue of the accuracy of the hand times. When they come frorm meets with skilled timers, the old hand times are pretty good. But when the timers are not well-trained what you will see is that the 'best' times will tended to have errors that under-estimate the correct time. If you make an error on the low side you are more likely to be in record territory than if you make an error on the high side; this effect is biggest in the shortest races, of course (for the two-mile the distribution of top times is much bigger than the distribution of timing errors).

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  • dukehjsteve
    replied
    in the past, .24 in the 100 ,200, and Hhurdles, .14 in the 2 one lappers.... don't recall the longer stuff.

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  • ESHSguy
    started a topic Timing conversions

    Timing conversions

    What is the general rule for converting hand times to electrical/automatic times? And how are they included on a school's top-ten lists in a particular event?
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