Defensive Contribution and QualComp/QualTeam

I think it makes sense to incorporate QualComp and QualTeam into DGVA.  It just doesn't make much difference.

I had been pondering whether it helped to utilize QualComp and QualTeam in computing DGVA from GAON and GAOFF. If I understand QualComp correctly, it is the average of (GFON/60 -GFOFF/60) – (GAON/60 – GAOFF/60) for all opponents faced. As such, it is in the same units as DGVA/60, and I think it makes sense to adjust GVA/60 accordingly. Presumably, I could scale DGVA/60 by multiplying by (1 + QC). It seems easier to add QC to DGVA/60. However, since QC is both offense and defense, and DGVA is just defense, I think adding 0.5*QC makes the most sense. Later, if/when I look at OGVA, I would add the other half.

 

QualTeam to me is a little less clear, since a player's performance influences the GAON/60 rates of his teammates. I'll think about whether there is a easy way to pull out the portion of QT independent of the player we are looking at. In the interim, from a symmetry standpoint if nothing else, we can subtract (to keep the signs and magnitudes correct) 0.5*QT from DGVA/60.

 

Looking at defensemen who had 20+ games last season, QC runs from +0.150 to -0.184. QT runs from +0.380 to -0..317. The ranges are greater than I would have guessed.

 

I reran the calculations using adjusted DGVA/60, and there really is not much change. The top 20 are basically the same. I listed them in Appendix A. Jack Johnson remain by far the worst, at -38.95 In looking at the differences between raw GVA and adjusted GVA, only 9 of 304 defensemen saw more than 2 goals difference. I listed the top 5 and bottom 5 in Appendix B. Zbynek Michalek goes up 3.95 due to QualTeam of -0.30. Conversely, Nicklas Lidstrom goes down 3.81 due to a QualTeam of +0.38

 

Appendix A

Top 20 Defensemen in Adjusted GVA

 

NAME	Minutes	QCOMP	QTEAM	RawGVA	AdjGVA
MARKFISTRIC	931.97	-0.09	-0.08	33.55	33.53
MARKGIORDANO	1280.84	-0.06	-0.08	20.71	21.00
MIKEWEAVER	971.74	-0.07	0.00	19.60	19.02
KEITHYANDLE	1289.86	-0.07	0.00	19.13	18.33
FRANCISBOUILLON	1296.81	-0.07	-0.01	18.80	18.22
MARCSTAAL	1474.36	0.14	0.06	16.96	17.96
TONILYDMAN	1049.89	-0.02	-0.02	17.15	17.18
ANDREWMACDONALD	751.64	0.02	0.08	17.41	17.06
JOSHGORGES	1332.50	0.01	-0.05	16.21	16.96
CHRISPRONGER	1437.46	0.10	0.18	16.77	15.85
SHELDONBROOKBANK	900.24	-0.07	-0.13	15.30	15.75
LADISLAVSMID	837.93	-0.07	0.02	16.06	15.42
KRISRUSSELL	1049.30	-0.08	-0.02	15.74	15.23
DENNISSEIDENBERG	1363.54	0.01	0.06	14.09	13.54
NICKBOYNTON	689.92	-0.03	0.03	13.80	13.43
SAMILEPISTO	1020.36	-0.05	0.03	13.60	12.93
DMITRYKULIKOV	969.68	-0.05	-0.07	12.61	12.82
RYANWILSON	874.13	-0.09	-0.09	12.38	12.37
JEFFSCHULTZ	1190.63	0.02	0.32	14.68	11.71

 

 

Appendix B

Biggest differences between Raw GVA and Adjusted GVA

 

NAME	Minutes	QCOMP	QTEAM	RawGVA	AdjGVA	Diff
ZBYNEKMICHALEK	1202.4	0.10	-0.30	-18.04	-14.09	3.95
DIONPHANEUF	1415.07	0.07	-0.10	-11.32	-9.29	2.03
RONHAINSEY	1299.2	0.09	-0.10	-3.03	-1.01	2.02
RYANSUTER	1482.56	0.03	-0.12	-8.15	-6.35	1.80
ROMANHAMRLIK	1336.5	0.06	0.30	-4.90	-7.67	-2.77
JEFFSCHULTZ	1190.63	0.02	0.32	14.68	11.71	-2.98
MIKEGREEN	1290	0.00	0.32	-7.96	-11.32	-3.36
BRIANRAFALSKI	1426.62	0.04	0.34	9.75	6.15	-3.60
NICKLASLIDSTROM	1434.18	0.06	0.38	5.26	1.45	-3.81