In the comments section for my previous post, Tom Tango pointed out that it would be interesting to see the breakdown of goals for and against when defensemen and forwards are missing from the lineup. For 2002-2008, we get the following:

 In In In Out Out Out
 +/- GF GA +/- GF GA
D 2.22 2.816 2.788 -9.67 2.707 2.825
F 3.21 2.833 2.794 -5.13 2.776 2.839

The results seem a little counterintuitive. Goal prevention drops the same amount when a forward and a defenseman are out of the lineup, while goal scoring drops much more when the defenseman is out. And the gap, 11.9 goals/82 lost defensive games to 8.3 for forwards, is nowhere near the almost 3:1 difference we saw when we just looked at wins and losses.

It's possible there's a problem with the ESPN GF/GA data - such things have cropped up before. Or including SO and OT goals is skewing the results. It's hard to say, but I'll take a closer look at the numbers.

Here's some yearly detail:

Forwards (~19 mins TOI or more)

Per 82 Games

Year +/- +/-GF +/-GA
2002-03 0.79 -5.88 -5.10
2003-04 10.73 -3.21 7.52
2005-06 13.83 -4.07 9.76
2006-07 8.34 -2.34 6.00
2007-08 8.15 -3.70 4.45

Average 8.34 -4.70 3.64

Defensemen (~21 mins TOI or more)

Per 82 Games

Year +/- +/-GF +/-GA
2002-03 5.84 -8.44 -2.60
2003-04 7.18 -5.89 1.29
2005-06 19.05 -11.46 7.59
2006-07 8.47 -5.963 2.51
2007-08 18.02 -14.40 3.62

Average 11.89 -8.93 2.96