| Sažetak | Osnovni cilj ovog istraživanja bio je utvrditi značajnost razlika u učinkovitosti napada i protunapada iz različitih zona u odbojkaškom setu. Istraživanje je provedeno na uzorku od 206 setova odigranih u 55 utakmica odbojkaške Lige prvaka za muškarce. Utakmice su slučajno odabrane iz ukupnog uzorka utakmica Lige prvaka u razdoblju od 2008. do 2012. godine. Analizirano je ukupno 10555 smečeva u napadu i protunapadu iz različitih zona odbojkaškog polja. Uspješnost smečiranja procijenjena je na ljestvici od 4 stupnja. Pri tome ocjena 1 znači pogrješku u izvedbi, ocjena 2 izvedbu nakon koje je suparnička ekipa u prednosti u daljnjem tijeku nadigravanja, ocjena 3 izvedbu u kojoj je ekipa koja smečira u prednosti u daljnjem tijeku nadigravanja, a ocjena 4 idealnu izvedbu tj. osvojen poen smečiranjem. Temeljem prikupljenih podataka izračunati su koeficijenti uspješnosti pobjedničkih i poraženih ekipa u napadu i protunapadu u cjelini, kao i po pojedinim zonama.
Na poduzorku od 11 setova, odnosno 503 smeča u napadu i protunapadu provedena je analiza pouzdanosti procjenjivača. Izvršena je usporedba mjeritelja u dvije vremenske točke s dovoljnim odmakom od 4 tjedna (test retest pouzdanost). Također je na istom poduzorku izvršena usporedba procijenjenih rezultata mjeritelja i eksperta. Maksimalna povezanost i nulte razlike između 2 mjerenja ukazuju na dosljednost procjenjivača u procjenjivanju događaja (smečiranih lopti u napadu i protunapadu). Visoka razina povezanosti i male razlike u procjenjivanju događaja između dva procjenjivača (autora istraživanja i eksperta) dodatno potvrđuju pouzdanost procjenjivanja autora ovog istraživanja.
Analizom razlika između pobjedničkih i poraženih ekipa u postotcima napada iz pojedinih zona utvrđeno je da se više od trećine ukupnog broja napada izvrši iz zone 4, a oko četvrtine iz zone 3. Nisu zabilježene značajne razlike u postotcima napada iz pojedinih zona između pobjedničkih i poraženih ekipa. Pobjedničke ekipe za 3% više smečiraju od poraženih iz zone 3, a za isti postotak manje smečiraju od poraženih iz zone 4.
Ni u protunapadu nisu zabilježene značajne razlike između pobjedničkih i poraženih ekipa u postotcima smečiranja iz pojedinih zona. Pri tome ekipe skoro polovinu od ukupnog broja smečeva izvode iz zone 4, a samo 10% iz zone 3. Pobjedničke ekipe nešto učestalije smečiraju u protunapadu iz zona 3 i 6, a poražene ekipe iz zone 4.
Analizom razlika u postotcima smečiranja u napadu i protunapadu utvrđeno je da su najveći broj smečeva u napadu i u protunapadu pobjedničke i poražene ekipe izvodile iz zone 4, a najmanji broj iz zone 6. Pobjedničke ekipe imaju značajno veći postotak smečiranja iz zona 4, 2 i 6, a značajno manji postotak smečiranja iz zone 3 u protunapadu u usporedbi s napadom. Kod poraženih ekipa testom razlika u postotcima utvrđen je statistički značajno veći postotak smečiranja iz zone 4 u protunapadu u odnosu na napad, kao i statistički značajno manji postotak smečiranja iz zone 3 u protunapadu u odnosu na napad.
Na cjelokupnom uzorku entiteta, analizom koeficijenata asimetrije (Skew) i zaobljenosti distribucije (Kurt) utvrđena je dobra osjetljivost prosječnih vrijednosti koeficijenata uspješnosti smečiranja u napadu i protunapadu u cjelini, kao i iz pojedinih zona. Time je ostvarena neophodna pretpostavka za primjenu parametrijskih metoda obrade podataka u daljnjim analizama.
Značajnost razlika u uspješnosti smečiranja u napadu i protunapadu između pojedinih zona utvrđena je analizom varijance. Razlike su analizirane posebno za pobjedničke i posebno za poražene ekipe. Dobivene su značajne razlike u učinkovitosti smečiranja u napadu i protunapadu iz različitih zona odbojkaškog polja kod pobjedničkih ekipa. Post-hoc analizom utvrđeno je da su pobjedničke ekipe značajno učinkovitije u napadu iz zone 3 u odnosu na zonu 4, dok u protunapadu post-hoc analizom razlika nisu dobivene značajne razlike u učinkovitosti smečiranja između pojedinih zona. Kod poraženih ekipa, u napadu nisu utvrđene značajne razlike u učinkovitosti smečiranja iz pojedinih zona. U protunapadu poražene ekipe su značajno učinkovitije iz zone 3 u usporedbi sa zonama 1 i 2.
Analizom razlika pobjedničkih i poraženih ekipa u uspješnosti smečiranja u napadu i protunapadu u cjelini, utvrđeno je da su pobjedničke ekipe značajno uspješnije od poraženih. Analizom razlika unutar pojedinih zona, utvrđeno je da su pobjedničke ekipe u napadu značajno uspješnije od poraženih iz svih zona, a u protunapadu iz zona 1, 2 i 4.
Dobiveni rezultati potvrđuju važnost smečiranja u napadu i protunapadu za pobjedu u odbojkaškom setu i ukazuju na specifičnosti smečiranja pobjedničkih i poraženih ekipa u napadu i protunapadu iz različitih zona. Rezultati istraživanja mogu biti od koristi trenerima u evaluaciji učinka igrača na utakmici, planiranju i programiranju trenažnog procesa i TE-TA pripremi ekipe za natjecanje. |
| Sažetak (engleski) | The primary objective of this study was to establish the significance of differences int he performance of attack and counterattack from various zones in the volleyball set. Research was conducted on a sample of 206 sets played in 55 matches of the Men's Champions League. The matches were randomly selected from the overall sample of Champions League matches in the period from the year 2008 to 2012. A total of 10555 spikes in attack and counterattack from various zones of the volleyball court were analyzed. The spiking efficiency was assessed on a four-point scale. Rating 1 denotes a performance error; rating 2 denotes a performance after which the opposing team has an advantage in the further course of the rally; rating 3 denotes a performance in which the spiking team has an advantage in the further course of the rally, while rating 4 denotes an ideal performance, i.e. a point scored by spiking. The collected data served as a basis for calculation of the coefficient of the winning and defeated team's efficiency in attack and counter-attack, both overall and by particular zones of the volleyball court.
A subsample of 11 sets or, respectively, 503 spikes in attack and counter-attack was used to conduct analysis of the assessor's reliability. Observer was compared at two points of time, with a sufficient time span of four weeks (test-retest reliability). Furthermore, the same subsample was used to compare results assessed by the observer and by an expert. Maximum correlation and zero difference between two measurements indicate consistence in assessment of the event (spikes in attack and counter-attack). The high level of correlation and small differences in assessment of the event between two assessors (the author of the study and an expert) further substantiate the reliability of assessment by the author of this study.
By analysis of differences between winning and defeated teams in percentages of attacks from particular zones, it was established that more than a third of the total number of attacks is performed from Zone 4, about a fourth from Zone 3. No significant differences were found in percentages of attacks from particular zones between winning and defeated teams. Winning teams perform 3% more spikes from Zone 3 than defeated teams; at the same time, they perform 3% less spikes from Zone 4 than defeated teams.
Neither were any significant differences found between winning and defeated teams in percentages of spikes from particular zones in counter-attacks, where almost half of the total number of spikes were performed from Zone 4, whereas only 10% came from Zone 3. Winning teams show a somewhat higher frequency of spikes performed in counter-attack from Zones 3 and 6, while defeated teams performed such spikes from Zone 4.
Analysis of differences in percentages of spikes in attack and counter-attack indicates that both winning and defeated teams performed the largest number of spikes in attack and counter-attack from Zone 4, while the fewest attacks came from Zone 6. Winning teams show a significantly higher percentage of spikes from Zones 4, 2 and 6, and a significantly smaller percentage of spikes in counter-attack, when compared to spikes in attack. As for defeated teams, the difference test in percentages showed, in terms of statistics, a significantly higher percentage of spikes performed from Zone 4 in counter-attack when compared to spikes performed in attack, as well as, in terms of statistics, a significantly smaller percentage of spikes performed from Zone 3 in counter-attack, as compared to spikes performed in attack.
On the overall entity sample, analysis of the asymmetry coefficient (Skew) and of the degree of peakedness of distribution (Kurtosis) showed good sensitivity of performance coefficient values of spikes in attack and counter-attack, both overall and from particular zones. Therefore, the required prerequisite was realized for employment of parametric methods of data processing in further analyses.
The significance of differences in the efficiency of attacks and counter-attacks among particular zones has been established by 1-way analysis of variance. The differences were analyzed separately for winning teams and for defeated teams. In the winning teams, significant differences were found in the efficiency of spikes in attacks and counter-attacks from various zones of the volleyball court. Post-hoc analysis disclosed that winning teams are significantly more efficient in attacks from Zone 3, as compared to Zone 4, while with regard to counter-attack, post-hoc analysis showed no significant differences between particular zones. With regard to defeated teams, no significant differences were found in the efficiency of spikes in attacks from particular zones. In counter-attacks, defeated teams are much more efficient from Zone 3, in comparison to Zones 1 and 2.
Analysis of differences in the overall efficiency of attacks and counter-attacks between winning and defeated teams showed that winning teams are much more efficient than the defeated ones. Analysis of differences between particular zones showed that winning teams are significantly more efficient in attacks from all zones, while in counter-attacks, they are more efficient in spikes from Zones 1, 2 and 4.
The obtained results substantiate the importance of spiking, both in attacks and counter-attacks, for winning a volleyball set, and indicate the specific values of spiking in attacks and counter-attacks from various zones, by winning and by defeated teams. The results of this study can be useful for coaches, in evaluation of the player's performance in the match, in planning and programming of the training process as well as in the technical and tactical preparation of the team for the tournament. |
