Natural Horsemanship is popular among many amateur and professional trainers and as such, has been the subject of recent scientific enquiry. One method commonly adopted by Natural Horsemanship (NH) trainers is that of round pen training (RPT). RPT sessions are usually split into a series of bouts; each including two phases: chasing/flight and chasing offset/flight offset. However, NH training styles are heterogeneous. This study investigated online videos of RPT to explore the characteristics of RPT sessions and test for differences in techniques and outcomes between amateurs and professionals (the latter being defined as those with accompanying online materials that promote clinics, merchandise or a service to the public). From more than 300 candidate videos, we selected sample files for individual amateur (n = 24) and professional (n = 21) trainers. Inclusion criteria were: training at liberty in a Round Pen; more than one bout and good quality video. Sessions or portions of sessions were excluded if the trainer attached equipment, such as a lunge line, directly to the horse or the horse was saddled, mounted or ridden. The number of bouts and duration of each chasing and non-chasing phase were recorded, and the duration of each RPT session was calculated. General weighted regression analysis revealed that, when compared with amateurs, professionals showed fewer arm movements per bout (p<0.05). Poisson regression analysis showed that professionals spent more time looking up at their horses, when transitioning between gaits, than amateurs did (p<0.05). The probability of horses following the trainer was not significantly associated with amount of chasing, regardless of category. Given that, according to some practitioners, the following response is a goal of RPT, this result may prompt caution in those inclined to give chase. The horses handled by professionals showed fewer conflict behaviours (e.g. kicking, biting, stomping, head-tossing, defecating, bucking and attempting to escape), and fewer oral and head movements (e.g. head-lowering, licking and chewing) than those horses handled by amateurs. Overall, these findings highlight the need for selectivity when using the internet as an educational source and the importance of trainer skill and excellent timing when using negative reinforcement in horse training.