Are NFL officials biased with their ball placement?

This is actually true. But the numbers don&#x27;t tell the entire story. Officials are trained to be biased towards a major yard line on change of possessions. Starting at a major line n these instances is insignificant to the drive. The upside being it is one less series where a measurement would ever be required.<p>It is a trade off of game flow (less measurements) vs a small inaccuracy where it doesn&#x27;t matter.<p>Take a notice next game. A punt always gets spotted on a major yardline where possible. A punt inside the 10 of course would not be possible. Rounding from the 2 to the 5 would have a huge impact. Or if it lands and comes to rest directly between two major lines.

One item that I did not see discussed is the effect of penalties, which are generally made in 5, 10, and 15 yard increments. This combined with the relatively standard 20 yard start position could have an enhancing effect, or be an alternate explanation for the phenomenon.<p>ex: The offensive team starts from the standard 20 yard line. Then during the first play, a pass is made, and &quot;block in the back&quot; is called against the defensive team. The penalty would be 10 yards, and would put the offensive team at the 30 yard line for the start of the play.

This is cool!<p>Couple notes - 1. If &#x27;normal&#x27; plays have a tendency towards a 10&#x2F;20&#x2F;30 yard line, what about plays where the ball placement is challenged? Don&#x27;t know if your dataset has this, but under your framework, we&#x27;d expect to see a more even distribution of placements because of increased attention, though probably still with spikes at the 1 yard line and goalline. 2. Even though it&#x27;s probably intuitive, the unimodal distribution of ball placements was cool to see.