Key stages in motor development Motor skills development is an important issue in all age groups. Utley & Astill (2008) admit that all human fundamental movement skills emerge before a person is born, and certain attention should be paid to the development of skills during first years of life. The stages of motor development are:  1. stage – first two years of life,  2. stage – between two and seven years of age,  3. stage – from seven to puberty,  4. stage – puberty onwards, and  5. stage – postural development. The session plan under analysis touches upon the third stage as the athletes are under the age of 11. The peculiar features of this stage are the following:   * Children have to elaborate upon the skills which have been already possessed;   * Children should be adapted to a variety of contexts;   * Children and tutors have to cooperate as any changes which take place during this period influence considerably further development of a child. Types of movement behaviour and skills There are four types of movement behaviour which have to be recognized:  1. Reflex movement is innate and lasts during the first year of life;  2. Rudimental movement is voluntary and takes place on the basis of predictable sequence;  3. Fundamental movement – is a kind of milestone of childhood development when a number of movement abilities take place.  4. Specialized movements are the types of movements which need to be refined in order to form specific skills appropriate for sport. Skills which should be developed as also of different types: open (in changing environment) and close (in more or less stable environment), gross (large muscles are involved) and fine (small muscle groups are considered), serial (when skills are formed in order to make a complex movement), discrete (well-defined actions with a clear end and beginning), and continuous (when obvious end and beginning are hard to discover). In the chosen session plan specialized movements which required the development of open, gross, serial skills are taken into consideration to promote successful training in rugby. Nature of skills vs. abilities There are a number of concepts which help to understand a true nature of skills and abilities. Schmidt & Wrisberg (2008) admit that the investigations of Fleishman and Henry have certain similarities as both of them believed that “abilities are independent of each other” (p. 172). Still, it is not always possible to understand how human abilities differ from skills. In fact, any ability is a skill, and any skill is ability. For example, the athletes have the ability to run for 10 rounds in 15 seconds. Such exceptional ability may be considered as a skill. Still, the ability to run cannot be changed, and the chosen skills may be improved. Professional coachers should take into consideration athletes’ abilities and improve the level of activities by means of development athletes’ skills. Theories of skill development Learning a new skill or ability is a complex activity, this is why it is better to use a certain theory and the already defined principles to understand properly the required process. Skills development may be characterized by several theories:  1. Fitts and Pos