What is the Most Important Volleyball Skill in the Women’s Game? Using Match Data from the 2012 Women’s Volleyball Olympics Games

INTRODUCTION In a previous blog post, I have attempted to answer what is the most important skill in volleyball.  In that blog post, I used men’s volleyball Olympic match data.  The results seem to show However, is this the same case in the women’s game?  I decided to do the same study but instead using women’s volleyball Olympic official statistics.

WHAT DID I FOUND OUT?  (FOR THOSE WHO WANT A QUICK ANSWER)

BUT… Clearly, this is not a definitive answer.  There are many sources of potential error.  No statistical testing was performed so it is not known whether any result is significant.  There could be operator error where the data is not entered into the system properly or where not all ball actions are called (e.g. see link).  Data may also be changed by the Omega operator that monitors the codes coming in (see link).  No inter-operator reliability testing was done (whether different statisticians will record the same performance in the same way) and operational terminology may not be clearly defined.

METHODOLOGY (FOR THOSE WHO WANT A LONG ANSWER)

I have compared a team’s tournament rank with their performance indicator rank.  There are two performance indicators for each 6 technical skill, except for setting where there is only one.  If their tournament rank matches their performance indicator rank then I have highlighted it green.  If it is one rank away then I have highlighted it orange.  If it two or more ranks away then I have highlighted it red.  I have also grouped the teams’ tournament rank to those who reached the semi-finals (1st-4th), teams that reached the quarters-finals but no further (5th-8th) and teams that did not progressed beyond the group stages (9th-12th).  No statistical testing have been performed so no significant results are known.

ATTACK ANALYSIS It can be seen that there is some agreement in attack as a performance indicator because there is few red squares.  However, there are not many green squares but the rank groupings show nice correlation.  There is certainly a difference between teams that did not progress beyond the group stages (9th – 12th) compared to the teams that did (1st – 8th).

Tour. Rank	Team	Spikes	Faults	Shots	Total	H%	H% Rank	AER	AER Rank
1	Brazil	459	126	470	1055	31.56%	3	3.643	3
2	USA	406	98	405	909	33.88%	1	4.143	1
3	Japan	434	142	500	1076	27.14%	6	3.056	5
4	Korea	426	148	464	1038	26.78%	7	2.878	7
5-8	China	377	128	402	907	27.45%	5	2.945	6
5-8	Dom. Rep.	286	113	327	726	23.83%	8	2.531	8
5-8	Italy	331	90	353	774	31.14%	4	3.678	2
5-8	Russia	350	98	349	797	31.62%	2	3.571	4
9-10	GB	158	102	247	507	11.05%	11	1.549	11
9-10	Turkey	282	123	279	684	23.25%	9	2.293	9
11-12	Algeria	146	109	268	523	7.07%	12	1.339	12
11-12	Serbia	196	106	228	530	16.98%	10	1.849	10
Tour. Rank	Team	Spikes	Faults	Shots	Total	H%	H% Rank	AER	AER Rank
1st – 4th		1725	514	1839	4078	29.70%	1	3.356	1
5th – 8th		1344	429	1431	3204	28.56%	2	3.133	2
9th – 12th		782	440	1022	2244	15.24%	3	1.777	3

SERVE ANALYSIS It can be seen with so much red squares, there is not association between serving and a successful outcome. From what I have seen in the elite game, there is always more service errors than service aces but Russia is the only time I have seen a positive Service %.

Tour. Rank	Team	Aces	Faults	Hits	Total	S%	S% Rank	SER	SER Rank
1	Brazil	31	58	630	719	-3.76%	7	1.871	8
2	USA	20	42	581	643	-3.42%	6	2.100	9
3	Japan	35	43	564	642	-1.25%	4	1.229	3
4	Korea	24	41	611	676	-2.51%	5	1.708	6
5-8	China	29	31	531	591	-0.34%	2	1.069	2
5-8	Dom. Rep.	15	44	375	434	-6.68%	10	2.933	11
5-8	Italy	26	32	466	524	-1.15%	3	1.231	4
5-8	Russia	21	18	530	569	0.53%	1	0.857	1
9-10	GB	19	44	234	297	-8.42%	11	2.316	10
9-10	Turkey	29	52	354	435	-5.29%	9	1.793	7
11-12	Algeria	20	32	209	261	-4.60%	8	1.600	5
11-12	Serbia	9	37	257	303	-9.24%	12	4.111	12
Tour. Rank	Team	Aces	Faults	Hits	Total	S%	S% Rank	SER	SER Rank
1st – 4th		110	184	2386	2680	-2.76%	2	1.673	2
5th – 8th		91	125	1902	2118	-1.61%	1	1.374	1
9th – 12th		77	165	1054	1296	-6.79%	3	2.143	3

BLOCK ANALYSIS Again, with the majority of the cells red, there is no correlation with blocking as successful to performance.  It may be able to distinguish lower ranked teams (9th to 12th) to the higher ranked teams (1st to 8th).  It is important to point out that a block outs (opposition attacks that comes off the block that leads to a point won by the opposition) is counted as a block fault, which I do not agree with.

Tour. Rank	Team	Blocks	Faults	Rebounds	Total	B%	B% Rank	BER	BER Rank
1	Brazil	90	172	261	523	-15.68%	6	1.911	6
2	USA	86	155	220	461	-14.97%	5	1.802	5
3	Japan	41	117	195	353	-21.53%	8	2.854	10
4	Korea	68	157	160	385	-23.12%	10	2.309	8
5-8	China	67	130	142	339	-18.58%	7	1.940	7
5-8	Dom. Rep.	48	74	129	251	-10.36%	2	1.542	2
5-8	Italy	59	87	165	311	-9.00%	1	1.475	1
5-8	Russia	74	128	196	398	-13.57%	3	1.730	3
9-10	GB	31	74	84	189	-22.75%	9	2.387	9
9-10	Turkey	42	75	112	229	-14.41%	4	1.786	4
11-12	Algeria	13	57	75	145	-30.34%	12	4.385	12
11-12	Serbia	25	76	73	174	-29.31%	11	3.040	11
Tour. Rank	Team	Blocks	Faults	Rebounds	Total	B%	B% Rank	BER	BER Rank
1st – 4th		285	601	836	1722	-18.35%	2	2.109	2
5th – 8th		248	419	632	1299	-13.16%	1	1.690	1
9th – 12th		111	282	344	737	-23.20%	3	2.541	3

SETTING ANALYSIS There is some connection between setting and a successful outcome, as shown by the few red squares and the groupings all green.

Tour. Rank	Team	Sets	Faults	Still Sets	Total	A%
1	Brazil	435	9	586	1030	41.36%	3
2	USA	373	6	486	865	42.43%	1
3	Japan	408	4	636	1048	38.55%	7
4	Korea	404	3	600	1007	39.82%	5
5-8	China	352	8	511	871	39.49%	6
5-8	Dom. Rep.	267	8	441	716	36.17%	9
5-8	Italy	311	8	433	752	40.29%	4
5-8	Russia	324	6	433	763	41.68%	2
9-10	GB	145	11	342	498	26.91%	11
9-10	Turkey	262	10	382	654	38.53%	8
11-12	Algeria	133	10	365	508	24.21%	12
11-12	Serbia	185	6	324	515	34.76%	10
Tour. Rank	Team	Sets	Faults	Still Sets	Total	A%
1st – 4th		1620	22	2308	3950	40.46%	1
5th – 8th		1254	30	1818	3102	39.46%	2
9th – 12th		725	37	1413	2175	31.63%	3

RECEPTION ANALYSIS It looks like Reception % (the percentage of reception that is kept in play) is a good performance indicator with only Turkey is anomaly.  The Excellent Reception % doesn’t look as strong.  It seems like getting the ball is play is more important than the quality of it.

Tour. Rank	Team	Excellent	Faults	Recep.	Total	R%	R% Rank	ER%	ER% Rank
1	Brazil	469	15	132	616	97.56%	1	76.14%	1
2	USA	350	19	128	497	96.18%	3	70.42%	6
3	Japan	385	19	138	542	96.49%	2	71.03%	5
4	Korea	398	31	174	603	94.86%	8	66.00%	9
5-8	China	373	25	135	533	95.31%	6	69.98%	7
5-8	Dom. Rep.	271	16	109	396	95.96%	5	68.43%	8
5-8	Italy	314	20	82	416	95.19%	7	75.48%	2
5-8	Russia	308	29	92	429	93.24%	9	71.79%	4
9-10	GB	178	26	148	352	92.61%	11	50.57%	12
9-10	Turkey	293	16	91	400	96.00%	4	73.25%	3
11-12	Algeria	189	31	145	365	91.51%	12	51.78%	11
11-12	Serbia	205	26	134	365	92.88%	10	56.16%	10
Tour. Rank	Team	Excellent	Faults	Recep.	Total	R%	R% Rank	ER%	ER% Rank
1st – 4th		1602	84	572	2258	96.28%	1	70.95%	2
5th – 8th		1266	90	418	1774	94.93%	2	71.36%	1
9th – 12th		865	99	518	1482	93.32%	3	58.37%	3

DIG ANALYSIS It looks like dig has no correlation with a successful performance.  The two worst digging team are either the champions or the last placed team.  I would point out that these percentages may be misleading.  As an operational definition, when opposition attacks makes contact with the floor, a dig fault is not charged.

Tour. Rank	Team	Digs	Faults	Recep.	Total	D%	D% Rank	PD%	PD% Rank
1	Brazil	391	166	152	709	76.59%	12	55.15%	11
2	USA	344	123	132	599	79.47%	9	57.43%	9
3	Japan	483	103	130	716	85.61%	1	67.46%	1
4	Korea	393	138	146	677	79.62%	8	58.05%	8
5-8	China	364	102	96	562	81.85%	5	64.77%	3
5-8	Dom. Rep.	325	74	94	493	84.99%	2	65.92%	2
5-8	Italy	331	81	112	524	84.54%	4	63.17%	5
5-8	Russia	335	108	109	552	80.43%	7	60.69%	7
9-10	GB	186	59	61	306	80.72%	6	60.78%	6
9-10	Turkey	256	61	86	403	84.86%	3	63.52%	4
11-12	Algeria	185	70	72	327	78.59%	10	56.57%	10
11-12	Serbia	157	68	69	294	76.87%	11	53.40%	12
Tour. Rank	Team	Digs	Faults	Recep.	Total	D%	D% Rank	PD%	PD% Rank
1st – 4th		1611	530	560	2701	80.38%	3	59.64%	2
5th – 8th		1355	365	411	2131	82.87%	1	63.59%	1
9th – 12th		784	258	288	1330	80.60%	2	58.95%	3

POINTS ANALYSIS It is unclear whether point scoring has associated with a successful outcome.  I am surprised because to win games you need to score points so point scoring skill should be important.  I found in every match I have statted, the team with the higher Points Efficiency Ratio (PER=Points/Faults) has won the match.  However, this analysis is not the difference between winning and losing but about successful and unsuccessful teams.

Tour. Rank	Team	Points	Faults	Total	P%	P% Rank	PER	PER %
1	Brazil	580	380	3943	5.07%	4	1.526	5
2	USA	512	320	3375	5.69%	2	1.600	2
3	Japan	510	325	3661	5.05%	5	1.569	4
4	Korea	518	380	3709	3.72%	8	1.363	8
5-8	China	473	322	3241	4.66%	6	1.469	6
5-8	Dom. Rep.	349	255	2523	3.73%	7	1.369	7
5-8	Italy	416	237	2777	6.45%	1	1.755	1
5-8	Russia	445	279	2956	5.62%	3	1.595	3
9-10	GB	208	257	1843	-2.66%	11	0.809	11
9-10	Turkey	353	276	2402	3.21%	9	1.279	9
11-12	Algeria	179	239	1802	-3.33%	12	0.749	12
11-12	Serbia	230	251	1887	-1.11%	10	0.916	10
Tour. Rank	Team	Points	Faults	Total	P%	P% Rank	PER	PER %
1st – 4th		2120	1405	14688	4.87%	2	1.509	2
5th – 8th		1683	1093	11497	5.13%	1	1.540	1
9th – 12th		970	1023	7934	-0.67%	3	0.948	3