# The Ball Response on the Beech Parquet Floors Used for Basketball Halls
## 3 Results and Discussion
### Choosing the Optimal Parquet Structure Depending on the Ricochet of the Ball
It can be seen from Figure 10 that the thickest parquet, respectively with a thickness of 25 mm, has the best reaction of the ball on average of 1.174 m; this means that the rigid structures (in this case, the rigidity being given by the greater thickness of the frieze parquet) are more suitable for floor basketball gyms. All type B structures had a good ball reaction above the minimum acceptable value of 1.0836 m. The energy absorption of the three types of structures with values of 6.61, 6.00, and 1.88% was lower than the limiting energy value of 6.69%, which means that from this point of view, all type B structures are acceptable for use in the case of basketball halls. Similar results were observed by [PERSON] et al. [18] by using eucalyptus wood, Same values were also found by [PERSON] et al. [8], where oak wood was used. Regarding the structures on the frame of softwood and beech wood shock pads, respectively the C-type ones, their analysis was made according to the number of taggers glued on the lower part of the structure, respectively with 13, 25, and 40 slippers. The results for each structure are presented in Figure 11.  
First of all, Figure 11 shows a significant increase in the ball's response as the number of wooden slippers increases. Thus, for the thickness of the parquet frieze of 20 mm, an increase of the ball response was observed from 1.1086 to 1.115 mm (a percentage increase of 2.6%) when the number of wooden taggers increased from 13 to 40 pieces. Analyzing each structure separately, it was found that there were two structures with ball response below the allowable limit: (1) the structure C/t = 20 mm/13 wooden taggers with a value of 0.966 mm and an energy absorption of 13.2% and (2) the structure C/20 mm/25 taggers with a value of 1.064 mm and an energy absorption of 7.7%. All the other structures had a very good ball response and a corresponding energy absorption, which means that they can be used successfully to make the floors of basketball halls. Similar results were obtained by [PERSON] et al. [14; 17] and others [10; 18; 27], which used beech parquet and similar structures. The analysis of type D structures was done as in the case of type C structures, depending on the thickness of the parquet strip (15, 20, and 25 mm) and depending on the number of rubber slippers arranged on the lower face of the structure, respectively 13, 25, and 40 pieces. From Figure 12, it is clearly observed that the increase in the slippers number led to the elasticity increase of the structure, and the ball's response decreased. For example, in the case of the 25 mm thick structure, the ball's response decreased from a value of 1.157 mm (for 13 rubber taggers) to 1.064 mm (for 40 rubber taggers), respectively a decrease of 7.9%. From this, it can be concluded that upon increasing the number of rubber taggers, the parquet structure will be more elastic, and the ball's response to touching the floor will be  
Figure 11: Ball response for C structure: (a) 13 wooden slippers; (b) 25 wooden slippers; (c) 40 wooden slippers. smaller. The same value of the decrease was in the case of energy absorption. The smallest decreases in the ball's response were observed in the case of the number of rubber taggers of 40 pieces, in which case all three structures did not exceed the minimum threshold of 1.083 mm and are not accepted for use [17; 27]. All the other six structures have exceeded the limiting values and thus are suitable for use for floors in basketball halls. Figure 12: Ball response for D-type structure: (**a**) for structure with 13 rubber slippers; (**b**) for structure with 25 rubber slippers; (**c**) for structure with 40 rubber slippers.