The dynamic systems theory stresses the interrelationship between the environment and the individual (Haywood, 1993). If manipulating the speed of the throw causes the performer to alter his/her pattern to a less mature pattern or an altogether new pattern (e.g., an underhand toss), the change, from a dynamic systems perspective, would be controlled by speed and not a motor program. Coordinative structures are also an important aspect of the dynamic systems theory. These exist when specific collectives of muscles and joints develop functional synergies, through practice or naturally, and act cooperatively to produce an action (Magill, 2004). If elite performers maintain the throwing pattern better than the novice throwers, then from a dynamic systems perspective, it would be because they have developed a stronger coordinative structure through practice. The purpose of this study was to determine the effects of altering the speed of the overarm throw on elite and novice throwing patterns and relating the results to the dynamic systems theory. Volunteers from the varsity baseball and softball teams of a NCAA Division II university participated as the elite throwing subjects (N = 36; 18 males, 18 females). Subjects were videotaped (saggital plane) throwing at a mat (1.5m x 0.9m and from a distance of 5.2m) for five trials at their preferred speed and monitored with a speed gun. They then performed five trials at full speed. After completing their trials at full speed, subjects threw half speed and one-quarter speed. The speed of their maximum throw determined the appropriate half and one-quarter speeds. Subjects continued to throw until the speeds targeted (half or one-quarter) were within plus or minus one mph of the specified speed. Participants received feedback from the test administrator as to whether they needed to alter the speed of their throw. The same procedure was followed for the novice throwers (fourth-graders from a local elementary school; N = 36; 18 males, 18 females). The videotaped data were analyzed using Mosher's Test for Overarm Throwing (1983) by two trained researchers (interrater reliability = 0.90). A two-way ANOVA and Scheffe multiple comparison tests were conducted and significant differences were found among the groups (F-Ratio = 65.62; p = 0.0001) and the treatments (F-Ratio = 54.04; p = 0.0001). Elite throwers were able to maintain form better than novice throwers, and the speed of the throw significantly affected throwing form. Thus, it was concluded that two major concepts of the dynamic systems theory were supported. Keyword(s): elementary education, gender issues, performance