Has anybody actually ever seen a contested sprint in which everyone goes in a straight line? Nobody complained about yesterday's Milan-Torino finish (cited only because of chronological proximity) but the distance between Demare and the right hand barrier at the end is not the same as a few seconds earlier. The current rule does not describe anything that riders can do, intend doing, or think they should do because it mandates an impossible absolute. It is equivalent to a school rule that all pupils must have highly polished shoes, but only applying it when a student is thought to have mumbled obscenities abut a teacher but there is no evidence.
Sprinter safety is not maintained by that type of rule, because it is so rarely applied. In so far as there is sprinter safety, it is achieved by a tacit balance between them not wanting to hurt each other, and them not wanting to be hurt. (What follows is obviously speculation, but not, I would suggest, far of what happens in every incident of sprint brinkmanship until its terrible conclusion) When DG moved a little to his right, he will have thought FJ would back off, or switch left loosing some speed. When he didn't. DG moved a little further: again FJ didn't back off. Please don't think that I am blaming Jacobsen, but this happened because of his extreme courage and determination not to be intimidated: Matthews stopped pedalling when Bouhanni shut the door on him, Fabio didn't and was still going for the win. Groenewegen kept moving right, because he thought he was showing more cojones, more determination to win, by doing so. And we praise our favourite sprinters for their determination and refusal to be baulked
If a rule about a straight line sprint is to be maintained, then it needs to be applied ridigly, so that no rider imagines for an instant that he will get away with it (just as rules about staying on the road surface need to be applied consistently and ruthlessly, and not come as a shock when they are applied). That means that straight approaches are necessary: it should be the UCI/national federation's responsibility to ensure that, enough of these right angles with 400m remaining (not an issue yesterday, but it often is). It means finding some way to encourage full width of the road gallops, rather than last 50m slingshots. And it may mean that for some time, until sprinters, managers and coaches get used to it, many stages in which the first several men over the line are relegated, and the guy coming 5th or so gets to be the one on the podium with the champagne. Because it is knowing that breaking the rule will always make the result impossible, and that it will get you disqualified even from 8th place (when that is a good result for you or your points accumulation) that things may change, not for so long as the rule is free to be broken until the point at which those who also frequently break it decide that you went too far this time, crossing some indefinable honour code.
Are the UCI sitting down today with all team managers to discuss what is a fair sprint?