There are players who historically perform better in the playoffs and who historically perform worse. Joe Thornton is a guy who performs worse, Justin williams is a guy who performs better.
With McDavid, his one playoff performance was statistically that of a guy who performs worse, but the sample size is small enough that I don’t think it’s fair to brand him as such and as long as he isn’t proven to be a guy who performs significantly worse, I would still take him over Crosby who historically performs about the same in playoffs and regular season.
I think the vast majority of the time, playoff performance disparities from the regular season to playoffs are well within reasonable margins of error, and within the context that playoff scoring is generally 3-5% lower (although it wasn't last season).
Williams and Thornton are probably known as the two biggest anomalies from this generation, and their deviations aren't even all that extreme.
Williams regular season career:
.63 PPG
.26 GPG
Playoffs career:
.67 PPG
.25 GPG
I gotta say these numbers are a helluva lot closer than I thought they would be. Can you honestly say you're not surprised by this?
Thornton:
Regular season:
.95 PPG
.265 GPG
Playoffs:
.77 PPG
.17 GPG
Anyway, after you factor is a ~4% adjustment that reflects league average scoring reductions in the playoffs, is an 18% reduction all that wild considering Thornton is on the extreme end of playoff disappointments with large sample sizes?
I just don't think it's enough to say with confidence that some players simply aren't suited for the playoffs.
I think the opposite is true: a brilliant regular season player (like McDavid) has a very high probability of continuing that brilliance in the playoffs.