There is a peculiar question about how accurate the times in a Head race should be. The obvious answer is: as accurate as possible; better than one hundredth of a second; like they have with photo finish. But a little thought shows that this is unrealistic, and that in fact as a timekeeper you are forced to choose what level of accuracy you can afford to provide.
The best human reaction times are around two tenths of a second. Most people (unscientific guess) are around three or four tenths. You can test yours here: Human Benchmark. I know some people are faster than that. But in the Olympics a reaction of less than one tenth is counted as a false start, because it is humanly impossible.
People have been timing athletics with stopwatches for a long time, and doing better than that. The way they achieve this is by: using reaction times, not anticipation times; and doing the same at the Start and the Finish. That way, the accuracy is the difference between reaction times, and not the reaction time itself. So with good concentration and good technique you may be able to get to an average accuracy of plus or minus a tenth.
But then you have to add the clock accuracy. I won't go into it again here, but all clocks drift, and only expensive clocks drift less than one or two tenths in the course of a race. A normal stopwatch is not sufficiently accurate. Nor is the clock in a video camera. And a computer or iPad clock is way off, even with time correction.
I am happy to accept that races run with different levels of accuracy. I am sure there are many races where one second is perfectly adequate. Even if, as a competitor, you would like it to be better, can you honestly say that it really matters? What I am not happy about is for competitors to believe that the times are accurate, when they are not. For me, the first rule is that times should not be given to a level of precision that is not warranted by the timing system. If the times are given to the full second, and if competitors are fine with that, then that's OK. But if times are give to the hundredth, and competitors "win" or "lose" by a few hundredths when in fact the times are accurate only to a second, then that is not OK.
I have tried to find out what competitors think is a reasonable margin to win or lose by. I have not been able to get a good answer. I was lucky enough to share the cab of a truck with an Olympic rower a few weeks back. I asked him about this. The immediate answer was "as accurate as possible". I think that competitors just don't engage with the idea that times are not absolute, but only plus or minus something. In regattas they are as precise as the photo finish, as we saw in the Olympic single sculls result. Maybe Head races just aren't that serious, and so the question is not asked.
I asked a top coach about this as well. His concern was more about time trials and crew selection. Here the times really do matter; and they may well be inaccurate. As we have more time trials, maybe we need to take more note of how accurate the timing is.
I find it is quite common to hear the view that manual times are only accurate to a second anyway, so why bother with trying to make the system more accurate than that. But then, if that's the case, don't publish times with a precision of less than a second; and see what competitors think.
One of the outcomes will be many more ties. I did an analysis of different races with the distribution of time differences: time distributions. It is quite remarkable how many competitors finish inside the same second as another. In some races, but not all, it affects the category winners too. I have wondered why this is. I think the underlying reason is that times are based on power and drag, and for most rowers the effective power band is fairly narrow.
So another way to look at the question is: would competitors be happy to have a lot of ties? Ties for first place overall, ties for place in category, ties for top ten. Personally I don't think so. For me, every result is the outcome of a lot of hard work. I want to take from it everything I can get! If I have a third place, then I would like to know it was third, and not equal with several others. it is quite obvious watching crews go by on the water that I can discriminate between them by much less than a second. One second is five to ten meters. It is a long way. We really should be able to do better than that.
But if that is the conclusion, then you need to have a timing system that is demonstrably more accurate. And many of them are not.