Among the several season-long trends for Denver’s offense that did not change Sunday with quarterbacks coach Klint Kubiak calling plays is the team’s third-down struggle. The Broncos converted just 3-of-12 overall against Las Vegas as their season conversion rate fell to 28.2%. Only Sunday’s opponent, Carolina, is worse in the NFL this year at 28% and only three teams in the past decade have played a full season at Denver’s level of futility. Head coach Nathaniel Hackett said Tuesday that Denver’s practice structure changes based on factors like short weeks or extra days and is also based on the health…