Hendrik Weimer<p>Every measurement device has a finite uncertainty. So, if the VAR in <a href="https://fediscience.org/tags/football" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#<span>football</span></a> says a player was offside by 5 cm, in reality, this is 5 ± x cm. If x is larger than 5, it's impossible to say whether the player was offside or not.</p><p>So, how big is x? For the HawkEye system used at <a href="https://fediscience.org/tags/Euro2024" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#<span>Euro2024</span></a> this information is a trade secret. However, for the sensor-equipped ball, it's reported that x is about 10: <a href="https://www.heise.de/en/background/EURO-2024-How-player-tracking-works-technically-9768864.html?seite=3" rel="nofollow noopener noreferrer" translate="no" target="_blank"><span class="invisible">https://www.</span><span class="ellipsis">heise.de/en/background/EURO-20</span><span class="invisible">24-How-player-tracking-works-technically-9768864.html?seite=3</span></a> For the players, who do not wear sensors, it's surely more than that.</p><p><a href="https://fediscience.org/tags/GERDEN" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#<span>GERDEN</span></a></p>