It is highly underestimated how complex one or zero turn MATS really are. Yes, they ARE very, very common. And yes, they are rapidly increasing in total percentage of US tasks!

Less experienced contest pilots all seem to struggle to get their head around the OLC tasks (one or zero turn HAT). I did. I still cannot stand them Becuase they are about local knowledge and guessing (luck) than anything else.

Pilot management of the "free" portion of the OLC task is very difficult. This is especially true if you are not a local pilot and are unfamiliar with the flying area visually. Errors in managing turnpoint order (and rules) has huge potential influence on the scores and ultimately the final contest results. Ones "ability" to quickly program expensive flight computers "on the fly" in order to better understand possible "free" HAT turnpoint combinations that will best use up available minimum time (vs. your competitor) is a critical success factor. This best combination of free turnpoints is constantly changing as conditions change along the task. This experience is fairly similar to the complexity (and luck) of wide (60 mile diameter) area TATs (slightly constrained OLC task). But nothing introduces luck like an OLC HAT task!

ASTs or "too long" MATs (very rare BTW) are far, far easier tasks to manage from a flight computer, strategy and local knowledge standpoint. Especially for beginners or people without expensive computers on board. A $50 handheld GPS is all you really need! With a Lomg MAT, Even 15 minutes of extra time for "free" turnpoints at the end of the task can dramatically change the result (from the end of the assigned portion). The free portion of a MAT essentially "destroys" the MAT task by introducing OLC like behaviors (and complexity and luck).

Study hard but the only way to get good at OLC tasks is local knowledge and a lot of practice (an expensive flight computer helps too). Expect more and more of them if the current trends continue. I would say 50% in 3-5 years is possible in the US.