# "Yellow" first down marker **URL:** \ **Category:** Factual Questions\ **Created:** [October 1, 2002, 2:10pm UTC](https://boards.straightdope.com/t/yellow-first-down-marker/130397 "2002-10-01T14:10:35Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![American\_Cheese](https://avatars.discourse-cdn.com/v4/letter/a/65b543/32.png) [@American\_Cheese](https://boards.straightdope.com/u/American_Cheese)\ **Post date:** [October 1, 2002, 2:10pm UTC](https://boards.straightdope.com/t/yellow-first-down-marker/130397/1 "2002-10-01T14:10:35Z")
After watching MNF last night this question occured to me. I am sure that anyone watching American Football has noticed that there is now a superimposed first down marker that only the TV audience can see. It looks like someone with a big yellow crayon drew down the middle of my TV screen so we can all see where the ball has to cross to make a first down. So my question is; how is this done? ---
**Author:** ![Spit](https://avatars.discourse-cdn.com/v4/letter/s/76d3ee/32.png) [@Spit](https://boards.straightdope.com/u/Spit)\ **Post date:** [October 1, 2002, 2:23pm UTC](https://boards.straightdope.com/t/yellow-first-down-marker/130397/2 "2002-10-01T14:23:25Z")
A LOT of effort goes into making that little yellow line **Cheese**. Here is a brief summary: > **[How the First-Down Line Works](https://entertainment.howstuffworks.com/first-down-line.htm)** > > The virtual first-down line that you see in many televised football games is something of a computer-generated miracle that home viewers have come to love. Find out how this line gets "painted" on the field without painting the players. ---
**Author:** ![American\_Cheese](https://avatars.discourse-cdn.com/v4/letter/a/65b543/32.png) [@American\_Cheese](https://boards.straightdope.com/u/American_Cheese)\ **Post date:** [October 1, 2002, 2:38pm UTC](https://boards.straightdope.com/t/yellow-first-down-marker/130397/3 "2002-10-01T14:38:08Z")
Wow, **Spit** , you werent kidding. That is a lot of info!! Thanks ---
**Author:** ![mookie117](https://avatars.discourse-cdn.com/v4/letter/m/aeb1de/32.png) [@mookie117](https://boards.straightdope.com/u/mookie117)\ **Post date:** [October 1, 2002, 4:24pm UTC](https://boards.straightdope.com/t/yellow-first-down-marker/130397/4 "2002-10-01T16:24:29Z")
Try this page for the answer. It sounds like it’s mostly sensors to tell the camera where it’s pointing and then geometry to draw the line. ---
**Author:** ![mookie117](https://avatars.discourse-cdn.com/v4/letter/m/aeb1de/32.png) [@mookie117](https://boards.straightdope.com/u/mookie117)\ **Post date:** [October 1, 2002, 4:25pm UTC](https://boards.straightdope.com/t/yellow-first-down-marker/130397/5 "2002-10-01T16:25:51Z")
[http://ask.yahoo.com/ask/20001012.html](http://ask.yahoo.com/ask/20001012.html) Oops. Here’s the page. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [October 1, 2002, 10:25pm UTC](https://boards.straightdope.com/t/yellow-first-down-marker/130397/6 "2002-10-01T22:25:10Z")
I don’t know if they’ve improved the technology in the past year or two, but the next time that Green Bay or Philadelphia is playing, watch the uniforms. The line gets superimposed over _anything_ green, not just the field. ---
**Author:** ![Manduck](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/manduck/32/256_2.png) [@Manduck](https://boards.straightdope.com/u/Manduck)\ **Post date:** [October 2, 2002, 1:43am UTC](https://boards.straightdope.com/t/yellow-first-down-marker/130397/7 "2002-10-02T01:43:43Z")
Maybe my memory is playing tricks on me, but it seems to me that the yellow line used to be more realistic-looking. In previous seasons it looked almost like it was actually painted on the field, but this year it’s a lot brighter and fake-looking. I wonder if that was done on purpose because they were getting tired of people thinking it was really there.