I have gotten into a drawn out discussion on precision and accuracy in autocross timing. A couple of engineers are saying that accuracy is unimportant and repeatability and precision are vital. I disagree and say that both are equally as important. Having a hard time getting in into a succinct paragraph that ends the topic. Even if it's a link to a white paper somewhere. Any thoughts?

http://ee.stlcc.info/130/accuracy.htm

That's a pretty good article.

Your friends are correct in the abstract, but you are correct in practical terms. Engineers tend to think in abstract terms, which is great for R & D but terrible for race timing, where stupid practical bulls*%#t trips more people up than anything. Example: Tissot falsely claimed a World 100m dash record for Justin Gatlin in 2006 because a Tissot technician had one setting wrong in their software. The result was truncated instead of rounded, and the world record was later nullified by the IAAF.

https://www.lindyssports.com/content.php?id=175

http://news.bbc.co.uk/sport2/hi/athletics/4989558.stm

Your friends are correct in that - in theory, and for example - if you've got a time base measuring autocrossers' starts and finishes perfectly and consistently, except the time base is precisely x.xxxxx second slow per minute, and all time bases used have the identical flaw, then you do not have a problem (except for absolute course records). But in practice, failures rarely present themselves in such perfect terms.

The fact that you're out in the field timing events and they're in a cubicle somewhere comparing pocket protectors makes the two viewpoints in this discussion very predictable.

The argument was made that "as long as it's repeatable it's fine". Well I for one am not fine with a repeatable 0.25 second error. Just what is the accuracy of their timing device, claiming to be accurate to the thousandth? As Jenna said on the phone, if it's not precise then it's probably not accurate either.

I am working on the club letting me time with an 8001 to check the accuracy.

Thank you Jim.