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The Relative Age Effect (RAE) has been the subject of many studies, but few have focused on professional athletes in individual sports. The aim of this study was to verify the existence of the RAE among elite senior female tennis players (top 100 players) in the WTA Rankings (n = 1000) in the years 2007–2016. The analysis was performed among top 100, resp. top 10 female tennis players, among players in 4 age subgroups and among left-handed (LH) and right-handed (RH) players. The existence of the RAE was assessed with the use of chi-square test (goodness of fit). More than half of top 100 players were born in first semester: both in individual years (53.0–63.0%) and in the whole observed period (58.4%). Significant RAE (ES medium) was observed in top 100 female players only in 2012 and 2016; significant RAE (ES small) was detected in the period of 2007–2016. Among the top 10 players, significant RAE (ES medium) was demonstrated during the whole period. No significant RAE (ES medium) was detected in the 17–18y subgroups, significant in 19–24y and 25–30y (ES small) as well as in 31–36y (ES medium). Although significant RAE was observed in the subgroups of LH and RH female players, ES was large only in the LH. The results contribute to the expansion of the knowledge about the reduction of the RAE existence in adulthood among coaches, athletes and tennis officials.

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The rolls for the hot rolling finishing stands are cast centrifugally as two or three-layer rolls. The working layer is called a shell. The material of the shell is selected according to the position of the respective roll in the final finishing stand of the rolling mill. Typically, a combination of rolls made of a high-chromium cast iron + indefinite cast iron or high-speed steel + indefinite cast iron is commonly used. Great attention has been paid to indefinite cast iron in recent years and this material received a number of modifications that led to the increase of material properties up to 20% in comparison to the ordinary indefinite cast iron. But the goals of the new generation of material for hot rollers were chosen higher: increasing of production about 30% and more. This material has specific physical properties, heat treatment requirements as well as rolling mill requirements as is stated in the paper. It is expected that introduction of this material will reduce the difference between wear of the front and finishing stands, which can extend rolling campaigns and have a positive effect on the reduction rolls exchanges, the grinding of the rolls and the reduction of downtime.