The race 50 meters freestyle swimming technique can be divided into four main phases. The start, swimming at the surface, the turn, and the finish. A Tachograph measuring system was used, which mainly analysed the speed of swimming at the surface. This measuring principle does not allow for accurate measurement of the speed after starts and turns and for that reason, we only evaluated the particular sections that were not influenced by the start and finish. We focused on the assessment of the ratio of the measured mean swimming speed, as measured by the Tachograph system, compared with the results of the current best racing performances from the 50 metre distance. The results were processed from the results of swimmers who participated in the semi-finals of the 2010 European Championship. Our goal was to establish which results of the swimmers measured by Tachograph are at a sufficient level. The objective of the work has been accomplished with the help of statistical methods. Furthermore, we have ascertained that our recorded results differ from the results of elite swimmers whose results have been gained from the evaluation of the sections of swimming at the European Championship. We assume that the race results of our measured swimmers will differ as well. The error may be caused not only by the lack of motivation of the swimmers but also due to the constraints that our measurement system caused.