By: Lydia Murray | Follow Me On Twitter @lydia_murray12
Advanced stats are becoming more common in hockey analysis these days. I’m a firm believer that you should never just pay attention to them but instead watch the player as a whole and do the good old-fashioned eye test. But, advanced stats do have a lot of merit, especially when trying to figure out why things are happening the way they are. With the round-robin tournament just two days away now, I decided to take a deeper dive into this Bruins team. In this article, I’ll be taking a look at some shot heatmaps for the Bruins offense at 5v5. Keep an eye out for an article coming soon with a heatmap of their defense and another with some heatmaps of power play and penalty kill. Also, be on the look for a deep dive one using skater good/bad/fun/dull graphs!
A Short Introduction to Shot Heatmaps
Before I begin, here’s a short overview of how to read these heatmaps for those of you who don’t know or need a refresher. This is just a basic overview of how these heatmaps work. If you want to see a really in-depth analysis, you can check one out (albeit of the San Jose Sharks) here. But anyway, these maps illustrate the number of unblocked shots (not necessarily on goal) for or against a team compared to the league average, and where those shots are coming from. Blue means that fewer unblocked shots are generated from a given spot than the league average, whereas red means more are generated than the league average. The deeper the color, the further away from the league average a team is from that spot. White means that shots are being generated at the league average from that particular spot.
With this in mind, on offensive graphs, blue is good, and red is bad. Obviously, you want your team to be generating a ton of shots, and ideally, they’ll be producing more than most other teams. On the other hand, for defensive graphs, the opposite is true. When an area is blue, it means that team is letting less unblocked shots through than the league average. It goes without saying that’s a great thing. The fewer shots that get through unblocked, the fewer chances an opponent gets to score.
Defining Areas of the Ice
Before I get started with the actual heatmaps, there’s just a few more things I want to go over. Pictured above is an example of the heatmaps you’ll see in this article as it was directly on the website. This is great on its own, but I decided to add a few more things to aid in my analysis.
As you’ll see, I’ve add a box and a trapezoid to the above graph (as well as made the crease more obvious). My apologies for the subpar photo editing job, I don’t have access to the best software and I’m not too skilled at it either. But, it’s good enough for the purposes of this article. Please note, these outlines may be off a little bit, but if they are, it’s not by much as I was as exact as possible with the tools I had.
I’ve added these areas to aid in my analysis of these graphs. The box area I have outlined is known as the “slot”, and shots from this area are considered “high danger”. The trapezoid is known as just that, and shots from that area are considered “medium danger”. Shots from anywhere else on the ice are considered “low danger.” According to this article, in the high danger area, shots have at least a 10% chance of going in. The article also says that shots from the medium danger area have a 3-10% chance of going in, while low danger shots have at most a 3% chance of going in.
To be clear, those percentages are averages, as some shots obviously stand a better chance of going in than others, even from within those areas. For example, a shot from the backdoor of the net that’s wide open has a much better shot than one that’s coming from right out front with the goalie square to it. But anyway, with all of that out of the way now, let’s get into the actual analysis these things.
Now, It’s Time To Analyze This Heatmap
Low Slot Bad, High Slot Good
The first thing that pops out to me when looking at this map is unfortunately not a good thing. As you can see, the Bruins are significantly below the league average in getting unblocked shots off in the slot, particularly right in front of the net. Granted, it’s a difficult task since there’s usually a lot of bodies there, but that’s not an excuse given they’re doing worse than most other teams. It’s disappointing. However, what this map doesn’t count is rebounds, and the Bruins get a lot of those in front of the net, so I don’t think they’re as bad there as this map makes them look. But regardless, it’s something they can definitely work on in the playoffs.
But, at the same time, they’re above the league average right at the top of the slot, and in my opinion, that’s a more dangerous spot. I’ve been taught to move out towards this area as a high school player, as it often results in more goals being scored. The same is true in the pros. Defensemen typically stay closer to the net, as there’s usually at least one player there, so the further out you move, the less likely they are to stick right to you. You often become the center’s problem at that point. So, you’re still covered by a player, but, it’s better to be covered by the center.
Why is it better to be covered by a center than a defenseman you may ask? Well, sometimes they’re easier to get away from, but that’s not always the case (Bergeron is a prime example of this). So, the biggest reason that being covered by the center is better is if the defensemen are closer to the net, as well as a forward or two, that’s a lot of bodies that you can use as screens for the goalie. If a goalie can’t see the puck, they can’t stop it (unless it hits them). So, while it’s disappointing to see so much blue closer the net, it’s nice to see a higher volume of shots from a little further out.
Bumper/High Slot Area Good
That whole red blob that’s mainly in the trapezoid but spills into the slot a little bit (right in the power play bumper area) is nice to see. It’s a great spot to shoot from because if the initial shot doesn’t go in, there’s typically a good rebound from that far out. Rebounds are how most goals are scored, and once you get in too close, there usually isn’t a good one. Goalies are better able to control shots from close in, and even if they can’t, it usually gets cleared by defensemen. Shooting from further out and getting those big rebounds means there’s a much better chance that someone will be able to jump on it and bury it. So, even though those aren’t technically considered “high danger” shots, they can be more dangerous than those that are, because most goals, especially in the NHL, don’t come from the initial shot, but from rebounds.
Left Circle Unsurprisingly Excellent
Another solid spot the Bruins shoot from according to this map is the left circle. This is unsurprising, as the Bruins have a lot of big shooters on that side. In particular, that’s where Pastrnak typically lets off his one-timer. For those that are a bit confused by that since he’s a right wing, it’s common to see players switch sides in the offensive zone, especially if they shoot different ways. That way, their sticks are in the center of the ice, meaning their forehand is towards the net. Otherwise, they have shoot across their body, which is not ideal from an angle standpoint, and it gives goalies that extra split second to get ready, which can make all the difference. It’s also much more difficult to one-time a puck on your off-hand, so all around it just makes sense to switch sides.
As good as most of the left circle is, there’s a big spot starting in the top of the left circle where the Bruins are shooting a little below the league average. That’s never great, but, the Bruins are never going to be shooting league average or above from every inch of the ice. It’s impossible for them to. So, with that in mind, if there are good spots for them to be shooting below league average from, that’s one of the big ones.
For the most part, it’s a weird angle to the net, especially if it’s a left shot player. Weird angle shots are not good because it’s lucky if it goes in on the initial shot, and if it doesn’t, it isn’t going to produce a good rebound. The angle a puck goes in at is the angle it comes back out at, so in all likelihood, that puck would be heading to the corner off a rebound (if it goes anywhere). It’s no good to anyone over there. So, yeah, it’s an area they could work on. But, it’s not a concern for me, even though much of it’s considered “medium danger” scoring chances. I’m sure it’s not for them either, as it’s not a big spot goals are scored or good rebounds are produced from.
Lots of Shots From the Left Point Too
One final spot the Bruins are particularly good at getting unblocked shots off in is the left point (up by/on the blue line). Again, this is not surprising. For starters, Chara fires off his slapshots from that spot, and those aren’t typically blocked. They’re so hard players don’t have time to react and step in front of them before they’re through (not that they’d want to). Plus, he usually doesn’t shoot unless he has a clear line.
But, the bigger reason the Bruins shoot from such a high volume at that spot is Krug. He’s the Bruins top offensive defenseman and is certainly not afraid to let a lot of shots fly. Yes, they get blocked sometimes, but he shoots so often, he makes up for the ones that are. His shots are also hard enough that, like Chara’s, players don’t typically have enough time to react and step in front of it once he lets it loose.
So, it makes perfect sense that the Bruins would be significantly above league average in this spot. It’s also a good thing because even though point shots don’t go in that often (despite the screens that typically form), they produce massive rebounds that can easily be pounced on by another player. Again, most goals in the NHL come from rebounds, not the initial shot, so shots from anywhere that typically produce good rebounds are great in my book.
Shooting More From the Right Circle Would Be Great
One area they should work on shooting at least a little more from in the playoffs is the right side. In a playoff series, it’ll be easier for a team to figure out how to shut them down from one particular spot, and they’ll almost certainly focus on that left circle. Yes, they (and especially Pastrnak) will probably still get a lot of shots through. But, if they can start shooting more from the right circle, it’ll catch the other team off guard. That’s a good thing. Plus, it’ll make it a lot harder for them to focus on just shutting down the left side.
The more they can spread out the defensemen, the better off they’ll be. Less concentrated defensive coverage will mean even more unblocked shots get through from the left than already are, which will almost certainly result in more goals. Plus, an increased volume of shots from the right should mean more will get through unblocked, which should result in a lot more goals too.
The Same Goes For the Right Point
I’d like to see them get more shots off from the right point in the playoffs for the same reasons I want to see more from the right circle. According to the heatmap, they’re around league average for most of it. That’s not awful obviously, but it’s a missed opportunity. Just like shooting from the right circle more will, shooting more from the right point will spread their opponents out more.
This will open up more lanes on both sides to get shots through, which almost surely means more goals. This is especially true for shots from the left point because they were already getting a lot of shots through from there despite already having a little more focus on them. So, if that side starts getting defended looser, they’ll be able to get even more through.
In short, the Bruins did a lot of things well shooting-wise this season. But, there are also a few areas they could work on for the playoffs. For the most part, they did a great job of getting a lot of unblocked shot through from the left side of the ice. They also did a good job of shooting from the bumper/high slot area, which, even though it’s classified as “medium danger,” is a really dangerous spot to shoot from. It usually produces decent rebounds if the initial shot doesn’t go in, which is always a good thing since the most common way goals are scored in the NHL (and really at all levels of hockey) is off of rebounds.
As for things the Bruins need to work on shooting-wise, they really need to start shooting more from the right side of the ice. As you can see from the map, they’re mostly league average over there. Obviously, that’s not terrible. But, if they start shooting more from that side, it’ll catch teams off guard. It’ll also make it so defenders have to spread out more and not just focus on one side of the ice, which will result in more shots getting through unblocked from all sides. Obviously, that’s a good thing, and it should result in a lot more goals for the team, which is something everybody wants.
They could also stand to shoot from right in front of the net a lot more. They were really bad at getting initial shots off from there this season. But, they did get a lot of rebounds there, which were not accounted for in this heatmap. So, it’s nowhere near as bad as it seems. However, it never hurts to shoot more, especially from a “high danger” area such as that.
Overall, the Bruins did a good job of shooting from dangerous areas of the ice this season. That’s unsurprising given how good they were this season. But, it’s nice to know that in this case, the advanced stats agree with everything else. Now there’s really no denying that the Bruins were really that good offensively this past season. Let’s hope they can keep that up throughout the playoffs!