Shots on goal is a stat that's heavily relied on when looking at how good a team is at controlling possession. However, they are not the most reliable because some arena's scorers have different definitions as to what counts as a "shot on goal." This should not be that complicated because, by definition, a shot on goal is a shot from the opposing team that is stopped by the goaltender or gets past him for a goal. That's easy to figure out, right? In theory, yes but the game of hockey moves at such a fast pace so there are bound to be scoring errors.
For instance, a puck that softly rolls in on a goaltender is sometimes recorded as a "shot on goal" and so is a harmless shot from 200 ft. away that ends up in the goalie's glove. Then you have dangerous chances that don't count as "shots on goal" because the goaltender never made a save, a shot that hits the goalpost is the most common example of this. Net-mouth scrambles also cause a lot of confusion for official scorers because there's a lot of bodies in the way and it's tough to tell how many shots on goal were actually recorded, especially because they are recording live. This is the reason why I have joined the scoring chance project and mainly look at those to judge players on the Hurricanes instead of just shots alone. Metrics like Corsi & Fenwick are also very helpful for judging possession but there's still a lot of noise to sort through with those stats, too.
The most interesting thing with shot-based metrics is how much they vary on home and road games. Every arena has a different official scorer and some team's shot differentials at home are pretty ridiculous. Don't believe me, just look at the numbers.
|TEAM||Home SF||Home SA||Road SF||Road SA||SF Diff||SA Diff||SD Home||SD Road|
Home SF = shots for at home per 60 mins, Home SA = shots allowed at home per 60 mins, Road SF = shots for at home per 60 mins., Road SA = shots allowed on the road per 60 mins., SF Diff = Difference in shots for between home and road games, SA Diff = Difference in shots allowed between home and road games, SD Home = shot differential at home, SA Road = shots differential on the road
There's a lot of information to process here, so I'll break a few things down.
- The Minnesota Wild have been the subject of ridicule for a lot of advanced stats folks, but there's something odd going on with the scorer at Xcel Energy scorer because Minnesota records much fewer shots at home than they do on the road. They are still getting pasted in terms of shot differential but they are recording fewer shots at home than anyone else in the league, which is strange when you look at their home/road differentials. Their difference in home/road shots for is the largest in the league among teams with a negative differential. I'm a little surprised that this hasn't been looked at more.
- The Bruins, Flyers, Avalanche and Panthers all record a hell of a lot more shots at home than they do on the road. Does getting the last shift benefit these teams more than others or are they getting some home cooking when it comes to what the scorer thinks.
- The Ducks give up about four more shots at home than they do on the road. They are near the bottom of the barrel when it comes to possession so this doesn't matter much, but it's interesting that they would be a middle-of-the-road team in shots allowed going by road stats, but at home, they are near the bottom.
- The Hurricanes, Lightning, Flames, Wild, Stars, Blue Jackets and Oilers appear to be surrendering much fewer shots at home than they are on the road. None of these teams appear to be dominant at home when it comes to wins/losses, though.
- The Penguins, Sharks, Red Wings and Senators are all getting a hefty amount of shots on goal per game no matter where they play.
- On the other hand, the New Jersey Devils are only averaging around 25 shots on goal per game at home and on the road but they are doing a fine job at preventing shots in both situations.
There's definitely some odd things going on with the official scorers in some arenas because the amount of shots that some teams are recording at home is pretty abnormal when comparing them with their road numbers. It's one of the reasons why looking at shots stats at face value can be deceiving. Whenever you watch the next Bruins game at TD Garden, take a look at the even strength shot count to see if Boston has a huge advantage or if they have around 35-40 shots recorded, then compare it with their next road game to see what the difference is. There's a good chance that it will be pretty high.