Just so I'm understanding what you're saying here, playing on a team that spreads it's ice-time among 4 units would necessarily depress a player's offensive totals - so how would looking at the percentage of goals a player was in on make up that gap? Common sense would dictate that would punish a player in a 4-line rotation even more. Correct me if I'm missing what you're saying here.
Also, Sv% is an averaging stat that does the same thing regardless of games-played (after a certain sample size is achieved), so it's not at all surprising it translates better to the playoffs (where some teams play 25 games and some play 5) than an adjusted counting stat like VsX. Is the idea that we shouldn't use counting stats to judge players at all? If not, it's a disgenuous comparison.
No. If the comparison is between forwards by position on a three line rotation and a four line rotation then the forwards on a three line rotation would have inflated ice time. So their numbers would have to be viewed accordingly.Point is understanding the impact of a three line vs a four line rotation.
Question would be how much of an impact does the 4th line have?
1959-60 Canadiens were a four line rotation team. The 4th line center, Ralph Backstrom scored 28 points:
http://www.hockey-reference.com/teams/MTL/1960.html
1959-60 Art Ross winner was Bobby Hull with 81 points.
http://www.hockey-reference.com/leagues/NHL_1960.html
Other than Beliveau and Henri Richard with 74 and 73 points respectively, the remaining top scorers were all playing on three line rotation teams. Distribute Backstrom's points amongst the top three Canadiens centers and the Ross result may be different.
Remove the weak scoring 4th line(4th and below highest scoring C/RW/LW) allows you to see how effective the top three lines could be with the inflated ice time.
SV% often explains why certain goalies only played 5 instead of 25 playoff games in a given post season.
Counting stats have their place in player evaluations but everything should be included in the count. Number of lines especially.