tag:blogger.com,1999:blog-10235575.post6694757348771003387..comments2024-02-04T15:48:48.193-05:00Comments on Adventures in Applied Math: Adventures in MeasurementRebeccahttp://www.blogger.com/profile/06927630155994067676noreply@blogger.comBlogger4125tag:blogger.com,1999:blog-10235575.post-34875586311768328332008-01-12T00:08:00.000-05:002008-01-12T00:08:00.000-05:00Hi Steve/With_Two_Flakes,Thanks for your comment. ...Hi Steve/With_Two_Flakes,<BR/><BR/>Thanks for your comment. I am glad to hear from an actual football official and to learn about some of the things you do to help minimize the errors. Thanks so much for sharing your perspective from the field!Rebeccahttps://www.blogger.com/profile/06927630155994067676noreply@blogger.comtag:blogger.com,1999:blog-10235575.post-39676231396995040652008-01-07T23:58:00.000-05:002008-01-07T23:58:00.000-05:00As a football official and a radar engineer, I was...As a football official and a radar engineer, I was very interested to see your metrology based review of our process of measurement using the chains. I don't think I have ever seen such a treatise before on officiating mechanics, it certainly made me reconsider and review the process. As you point out - small angular errors can make a difference. Consider my line of work, a small angular error when measuring the position of an aircraft at a range of 250 miles can lead to an error of rather more than the length of a football!<BR/><BR/>Your point regarding assessment of the point of forward progress of the ball when a play is stopped is quite valid and is one of the toughest things in football officiating. It is drummed into sideline officials (who almost always are the ones to judge progress) to be as accurate as possible. A technique to help with this is, where possible on the play type and (most important) safe to do so, to slide up the sideline with their body facing the field using a boxer style shuffle. Also stressed is to "square off" before coming infield, ie do not run in on a curving path to mark the progress spot.<BR/><BR/>Sometimes a better view is obtained by an official on the far side of the field as he has a shallower angle to the play <BR/>this is what we call a "cross-field" mechanic. He may have the disadvantage of being far from the play, but can have angular advantages in judging progress.<BR/><BR/>A couple of things you should know about the measurement process. We have to assume the field has been accurately marked and that the hash marks in the middle of the field will match those at the sidelines.<BR/>When the chain is set on the sideline for a new 1st down, the other officials will communicate the ball position to the Linesman (who controls the chain crew). The Linesman does not control the placement of the back stake by eye alone. The ball might be "nose on" to a yardline, "tail on", midway between or straddling a line.<BR/>Once the back stake is set, then a linesmans clip will be attached to the chain on the nearest edge of the nearest 5 yd line. This enables the chain to be set again when moved infield for a measurement. <BR/><BR/>You can guarantee that if a 1st down is made by a couple of inches then the defense will complain about the "generous" progress spot and vice versa by the offense if its 4th and inches. As officials, we are in a no-win situation out there. <BR/><BR/>As an engineer, I feel that the measurement process (when run properly) has as much accuracy as could be expected in the circumstances and that our procedures are fit for purpose.<BR/><BR/>Nevertheless, I don't like to get complacent about such things. Like many other disciplines, the world of officiating can sometimes be resistant to change or to the review of established practices. Your article coming as it did from a different viewpoint was valuable in making me re-assess the measurement process and i will certainly be bringing it to the attention of some of my colleagues.<BR/><BR/>Steve (aka With_Two_Flakes)<BR/>British American Football Officials AssociationAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-10235575.post-54373401269451993612007-10-14T21:14:00.000-04:002007-10-14T21:14:00.000-04:00Wow, a real metrologist, commenting on my post! G...Wow, a real metrologist, commenting on my post! Georgia, I will definitely be joining in the celebration of "World Metrology Day!"Rebeccahttps://www.blogger.com/profile/06927630155994067676noreply@blogger.comtag:blogger.com,1999:blog-10235575.post-92078728750335847132007-10-14T20:24:00.000-04:002007-10-14T20:24:00.000-04:00I enjoyed your foray into metrology. I hope you w...I enjoyed your foray into metrology. I hope you will join in the celebration of "world metrology day" on May 20 (each year.) Next year the theme will be metrology in sports - and you've already gotten a head start!<BR/><BR/>Georgia (NIST Weights and Measures)GHarrishttps://www.blogger.com/profile/06335445109948553341noreply@blogger.com