Tunnel vision is another symptom of a noob player. Some players really focus on getting last hits and fail to pay attention to their mini map, causing other lanes to get ganked unexpectedly. Calling missing is a simple solution to a potentially devastating error in judgement. Calling missing is especially important if you are playing in the middle lane, as a lot of mid heroes, such as Pudge and Bloodseeker, have strong ganking potential early on. Failing to call missing can lead to heroes snowballing out of control and plenty of smarmy "gg ez mid" responses from your teammates. As time goes on, players will learn to correctly predict when a hero is actually missing. However, calling missing often is always a better choice than not saying it at all. If you have the slightest intuitive feeling that one of the heroes in your lane is doing something else, do not hesitate to call missing. More often than not, the enemy is planning an ambush on your teammates. The trick is to always pay attention to your mini map. Since the map never changes, players should try to memorize the most common routes other players take to move around.
Film junkie, casual hardcore gamer, and human music database. Learned how to write so that I could share my ideas and justify the hundreds of hours I've spent glued in front of a screen. Follow me on Twitter for my less formal musings on geek culture.