Ever since swimming equipment became more available like swimming treadmills that could be combined with diagnostics, video technology and computer equipment, there was progressively more and more obtained knowledge that can provide crucial information which lead to improved performance. In recent decades, swimming has seen a great jump in quality and quantity. This trend is not the result of chance, but the result of close cooperation between kinesiology science and other scientific and technical knowledge. Along with the progress of science and technology, there has also been the development of tools that can can be used in sports without disturbing the athlete when performing a specific action in water. It can be inferred that swimming is progressing, considering the results of the first official competitions and today's contemporary ones. The purpose of this paper was to analyze and compare the data of the competitive swimming race in the 100 m butterfly discipline held in year 2021 at the World Championship in Abu Dhabi. Three swimmers were analyzed: Croatian swimmer N.M. (he was placed 16th in the semi-final race so he didn't take part in the final race), the swimmer who won the 100m butterfly event M.R., and the last swimmer that took place in the finals qualified as 8th A.M. The paper compares performances in certain parameters (stroke length, stroke frequency, swimming speed, etc.), with the ultimate goal of identifying deficiencies so that swimmers can work on improving them. Data were processed with the Statistica 14 software package, while Student t-test for independent samples was used to determine differences between swimmers. The results of the research confirmed that the null hypothesis was not confirmed and there was no statistically significant difference among swimmers among variables: stroke frequency, stroke length and swimming speed.