Wow! That's an impressively thorough evaluation of Perreault's acomplishment, seventieslord.
As the creator of this particular version of adjusted plus-minus, I'll add a little more detail on Perreault. Here is a breakdown of his adjusted plus-minus for the different periods of his career.
Player | Year | Seasons | $ESGF/G | $ESGA/G | R-ON | R-OFF | XEV+/- | EV+/- |
AEV+/-
|
/82
|
SH%
| PP% |
$PPP/G
| $ESP/G
Gilbert Perreault | 71-74 | 3.68 | 0.87 | 1.06 | 0.82 | 0.82 | -39 | -57 |
-17
|
-5
|
6%
| 86% |
0.49
| 0.61
Gilbert Perreault | 75-80 | 5.83 | 1.02 | 0.79 | 1.28 | 1.39 | 99 | 107 |
8
|
1
|
4%
| 76% |
0.48
| 0.79
Gilbert Perreault | 81-84 | 3.35 | 0.90 | 0.77 | 1.17 | 1.15 | 23 | 36 |
13
|
4
|
24%
| 55% |
0.28
| 0.67
Gilbert Perreault | 85-87 | 2.13 | 0.74 | 0.74 | 1.00 | 1.08 | 7 | 0 |
-7
|
-3
|
27%
| 5% |
0.25
| 0.56
Gilbert Perreault | 71-87 | 14.98 | 0.92 | 0.84 | 1.08 | 1.12 | 89 | 86 |
-3
|
0
|
12%
| 66% |
0.40
| 0.68
Perreault appears to have started off as a talented scorer and very productive on the power play. However, on a weak even-strength team, Perreault's on-ice results were identical to his off-ice results. This suggests that he wasn't playing a strong 200-foot game. His even-strength results would improve, however.
His prime from 1974-75 to 1979-80 is particularly interesting. This is the period of his career that makes his reputation. Perreault was a plus player during the 75-80 period, with a fine 1.28 GF/GA ratio. However, Buffalo had a 1.39 GF/GA ratio with him off the ice, meaning that his adjusted plus-minus is essentially zero.
If Buffalo had particularly strong goalies and defense corps*, this would be a fair rating. However, the truth isn't so simple. As seventieslord pointed out, Buffalo had a second line that was dominant at even-strength. Ramsay, Luce, and Gare drove Buffalo's success during those years at least as much as Perreault's line did, and probably more. Perreault's even-strength results suffer in comparison to theirs, but the question is whether that's a fair comparison.
Perreault's greatest contributions probably came on the power play. Here are the top power play scorers from 1974-75 to 1979-80. (Power play assists from 1975-76 on compiled from the Hockey Summary Project data, estimated for 1974-75.)
Player | GP | PPG | PPA | PPP |
PPP/G
Marcel Dionne | 470 | 81 | 155 | 236 |
0.50
Guy Lafleur | 462 | 90 | 136 | 226 |
0.49
Denis Potvin | 421 | 55 | 149 | 204 |
0.48
Phil Esposito | 472 | 109 | 113 | 222 |
0.47
Bryan Trottier | 387 | 65 | 104 | 169 |
0.44
Gilbert Perreault | 466 | 56 | 140 | 196 |
0.42
Darryl Sittler | 447 | 81 | 96 | 177 |
0.40
He wasn't on the level of the top power play scorers, but was still among the best at his peak.
In his post-prime years in the '80s, Perreault was no longer an elite scorer. While he was still a solid contributor, he was not a difference maker - more like a second line center on a good team or a first line center on a weaker team. He wasn't an elite power play scorer anymore, and was basically even at even-strength as his scoring dropped off. He did start killing penalties - evidence that his defensive game improved as his offensive game declined.
*This topic merits further research, particularly since SV% results from these years are coming out.
I think this is a fair assessment. Personally, I see him as comparable to Hawerchuk - centers who were very good to excellent but not elite scorers, were not distinguished on the defensive end, and brought much of their value on the power play.