When Bill McCreary whistled Alex Ovechkin for a highly questionable third period roughing penalty last Monday in Ottawa, CapsNation was hardly surprised - it was merely McCreary's blatant anti-Caps bias rearing its ugly, mustachioed head yet again.
But fans and non-rooting onlookers alike wouldn't necessarily have been wrong to have expected a call in that situation from McCreary based on where the game was being played, not which teams were playing it. It turns out that Billy Mac has demonstrated a bit of a home team bias in his years wearing the stripes. Dating back to 1993, and including playoffs, visiting clubs have received 11.75% more penalties than their hosts in McCreary-reffed games. [One note on the more than 25,000 lines of data - and huge thanks to Gabe at BtN for providing it - there are plenty of "missing" games, but they seem to be random enough that the data that is there is still good.]
That a visiting team would be penalized more than a home team isn't terribly surprising. One would expect that home ice advantage, if it exists (and it does), would lead to a bit of pressing on the part of the disadvantaged squad and that, combined with the crowd's partisanship, might impact the way the referees call a game. And that's precisely what the data shows - that over the 15,363 games analyzed, road teams were dinged for 5.82% more penalty minutes than home teams.
But McCreary's home-team bias sticks out at more than double the average rate... and he's not alone. Have a look for yourself after the jump.[Notes: Minimum 50 games in the data available; Active referees per National Hockey League Officials Association in italics; Home Team Win % excludes ties.]
|Referee||Games in Data||Road PIM % more than Home PIM||Home Team W%|
|Justin St. Pierre||242||6.84||49.2|
Hell of a table, eh? Oh, and if you're looking for our buddy Mr. van Massenhoven, as I noted, there were holes in the data, and apparently one of those holes swallowed up Dutch surnames.
Anyway, there's an awful lot in that table and, it's worth noting that it includes both pre-and post-lockout games and one- and two-man refereed matches. But whether we're talking "new" NHL with it's heightened enforcement of the rules on the books or the not-so-freewheelin' '90s shouldn't make a difference when we're looking at which team is getting whistled more. Neither should whether a referee was on his own calling a game (though obviously the calls made are not fully within one man's control in games with two referees)...but it does, albeit the difference is small. McCreary, for example, doled out 10.0% more penalty minutes to visiting teams than he did to home teams in the 365 games analyzed in which he was the only referee and there was a 12.9% difference in games in which he had a partner, and that differential is pretty much in line with the overall difference here - visiting teams were assessed 6.74% more penalty minutes than their hosts in dual-reffed games and 4.26% more when only one referee was out there.
To put all of these number in some perspective via an example, a referee with a 10% "bias" here who calls ten minor penalties on home teams over the course of two games will whistle the visitors just one more time over that span. So it's not much, but it obviously can be the difference between winning and losing on any given night.
Bottom line? Seeing that Bill MCreary is going to be calling a game featuring your team isn't in and of itself a reason to panic, but if your squad isn't the home team, you should have some idea of what to expect.
Post script: I see BtN has tackled this today as well. Go read another take with similar results when you get a chance.