With the 21st overall selection in the 2012 NHL entry draft, the Calgary Flames went way off the board and selected high school hockey player Mark Jankowski. Drafting high school hockey players is generally a crap shoot with scattered high end talent, but the majority of those talented players are drafted out of Minnesota or Massachusetts. Jankowski played for a Canadian high school team, so he was measured while playing against garbage competition (trust me, I played Ontario high school hockey and by NHL standards I was a garbage player). From 1990 - 2005, the only player drafted from a Canadian high school to play a game in the NHL is Colin Greening (drafted 204th overall out of Upper Canada College).
The higher the level of competition you watch a player play, the more reliable the scouting forecast will be. A player who can be totally dominant against weak competition can be equally terrible when playing against higher quality competition. It's entirely plausible that Mark Jankowski could develop into a good professional hockey player, but there's a chance he could advance to Canadian junior or the NCAA and absolutely suck. Is that a risk that a team like the Calgary Flames can afford to take? This is a team that has missed the playoffs for the past few seasons yet refuses to engage in a true re-building process, dooming themselves to mediocrity (consistently making bad draft picks doesn't help either).
From a probability point of view; players drafted from a Minnesota high school hockey team have a 35% chance of playing a game in the NHL, a 14% chance at 160 NHL GP. Those drafted out of Massachusetts have a 26% chance at 1 NHL GP and a 10% chance at 160 NHL GP. Players drafted from high schools everywhere else in North America have a 17% chance at playing 1 NHL game. The sample size for Canadian high schools is tiny, and the reason for its miniscule proportion revolves around the best young Canadian prospects playing junior or AAA. Pierre McGuire on TSN could hardly contain his excitement when Jankowski was drafted, explained largely by his association with the Jankowski family. It was biased excitement. Pierre could end up looking silly for his enthusiastic outburst, sooner rather than later.
HONORABLE MENTION: In the possible bad draft pick category is Hampus Lindholm. How far can one bike test at the combine raise a player's draft status? Enough to go 6th overall. His endurance is "off the charts", which is a great trait for a prospective professional athlete; but that seemed to be all anyone talked about. If you watched the draft, you saw tons of video of him riding a stationary bike, not so much of him playing hockey. I'm far more concerned about a prospect's ability to play hockey than I am about bike riding ability. Teams can put players on offseason training programs to improve conditioning, but you can't teach talent. Lindholm could very well develop into a quality professional hockey player, but there is a risk in putting too much value or focus on "the combine" rather than on ice evaluation. Defensemen drafted out of the Swedish lower divisions have a 39% chance of playing in the NHL, those drafted out of the Swedish Elite League have a 57% chance.