In one respect I agree with everything that has been said re:accuracy of hand timing v. using video and then whatever method to count or better motion analysis software (though with the latter, unless you have a multiple camera set up, one for every hurdle if you are using a side view, indoors it is very unlikely you will be able to set up far enough away to get all flights or the touch down points anyway without someone walking into frame between the camera and the athlete; if you are using a single camera at an obtuse angle, say from about the 4th hurdle if indoors, it will be next to impossible to get the actual feet touching down…or that has been my experience)
All of that said I pretty much do what you did, HT multiple TDs, and while I discount the accuracy, unless there is one very bad one and even the the compounding error comes into play, I do look for patterns so, for example if the TD times are getting progressively more I assume the athlete is slowing and the visual along with athlete feedback usually bears this out…you have to look at it all with a jaundiced eye but I feel it can be a tool none the less; I have found there are a few pretty “typical” patterns, the slowing one I already mentioned, an acceleration until about the 5th hurdle (which in many peoples’ view is “correct”) and the “every second one” which is the one you give;
take video of a full pass a couple of times and I would guess you will see the athlete does something a bit different on the last stride before the “fast” compared to the “slow”, betting the slow will be closer to the hurdle as well, and whatever “it” is is resulting in more flight time or contributing to a longer, time wise, trail leg touchdown.
