## 3 Results  
Table 1 represents the reliability coefficients of the tests. The results were within the range of [PERSON]'s alpha coefficients of 0.38 to 0.90, interitem correlation coefficients were 0.38 to 0.89, and coefficients of variation were 0.11 to 0.39. The highest level of reliability was observed for the SJH and AJH (0.89 and 0.87 for ICC, and 0.89 and 0.87 for [PERSON]'s alpha, respectively), as well as for covered jumping distance during the performance of an attack jump and number of block jumps (0.89 and 0.85 for ICC, and 0.90 and 0.86 for [PERSON]'s alpha, respectively). No significant differences between the tests were noticed (the biggest difference was in covered jumping distance during the block jump performance: 0.43 for ICC and 0.37 for CA, respectively). The lowest level of reliability (validity) was observed for BJH (0.38 for ICC and CA). Figure 4 shows the average jump height values during serve, attack, and block. The analysis of SJH by volleyball players at various positions showed statistically significant differences (\(P<0.05\)) among the middles (M1--46.51 \(\pm\) 11.12 cm and M2--46.75 \(\pm\) 11.53 cm), receivers (R1--64.44 \(\pm\) 15.03 cm, \(P\) = 0.000054 and R2--61.89 \(\pm\) 10.07 cm \(P\) = 0.0003), and opposites (O--65.16 \(\pm\) 11.12 cm, \(P\) = 0.00002). Similarly, such differences were observed among the setters (S--48.31 \(\pm\) 12.61 cm), receivers (R1--64.44 \(\pm\) 15.03 cm, \(P\) = 0.0002 and R2--61.89 \(\pm\) 10.07 cm, \(P\) = 0.0011), and opposites (O--65.16 \(\pm\) 11.12 cm, \(P\) = 0.00002). The receivers and the opposites showed higher jump height values during serves. Statistically significant differences in BJH were found between the middle M1 and receiver R1 (\(P\) = 0.0117), the middle M2 and the receiver R1 (\(P\) = 0.0075), the middle M1 and receiver R2 (\(P\) = 0.0124), and the middle M2 and receiver R2 (\(P\) = 0.0081). No statistically significant differences were noticed in attack jump height. The results of the comparison between JFD and serve, attack, and block for the players at given positions (Table 2). \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Parameter**} & \multicolumn{2}{c}{**Mean \(\pm\) SD**} & \multirow{2}{*}{**ICC**} & \multirow{2}{*}{**CA**} & \multirow{2}{*}{**CV**} & \multicolumn{2}{c}{**CI**} \\ \cline{3-3} \cline{5-6}  & **(cm)** & & & & **–95\%** & **+95\%** \\ \hline Ht. S & 55.53 \(\pm\) 15.51 & 0.89 & 0.89 & 0.15 & 52.73 & 58.33 \\ No. of S jumps & 2.41 \(\pm\) 1.85 & 0.48 & 0.49 & 0.39 & 13.25 & 14.87 \\ dist. of S jump & 164.12 \(\pm\) 59.48 & 0.55 & 0.53 & 0.19 & 150.42 & 170.10 \\ Ht. A & 65.22 \(\pm\) 11.25 & 0.87 & 0.87 & 0.11 & 63.00 & 67.44 \\ No. of A jumps & 4.08 \(\pm\) 3.99 & 0.56 & 0.60 & 0.38 & 24.06 & 28.87 \\ dist. of A jump & 126.69 \(\pm\) 37.03 & 0.89 & 0.90 & 0.13 & 119.10 & 130.41 \\ Ht. B & 48.69 \(\pm\) 10.22 & 0.38 & 0.38 & 0.29 & 46.84 & 50.54 \\ No. of B jumps & 5.26 \(\pm\) 4.31 & 0.85 & 0.86 & 0.37 & 28.29 & 33.04 \\ dist. of B jump & 96.43 \(\pm\) 34.19 & 0.43 & 0.37 & 0.26 & 137.86 & 151.03 \\ \hline \hline \end{tabular} Ht. – height; no.—number; dist.—distance; S—serve, A—attack, B—block; ICC—interitem correlation coefficient; CA—[PERSON]’s alpha reliability coefficient; CV—coefficient of variation; CI—confidence interval.  
\end{table} 
Table 1: Descriptive statistics and reliability coefficients for the tests used in this study. Figure 4: The results of the comparison between jump flying distance (JFD) and serve, attack, and block for the players at given positions (R1, R2—Receiver; S—Setter; O—Opposite; M1, M2—Middle blocker). Significant differences (\(P<0.05\)) were noticed between the average values for all JFD ratios during jump serve, attack, and block jump (Table 3). Taking into account the average JFD of attack jumps, the middles (M2) covered a statistically significantly shorter distance than the opposite players O (\(P=0.00874\)) and receiver P1 (\(P=0.0344\)) and P2 (\(P=0.0207\)) (Table 2).