NHL coaches must strike balance when using analytics

The Coaches Room is a regular feature throughout the 2019-20 season by one of four former NHL coaches and assistants who will turn their critical gaze to the game and explain it through the lens of a teacher. Paul MacLean, Rob Zettler, Rob Cookson and Randy Carlyle will take turns providing insight.
In this edition, former San Jose Sharks assistant Rob Zettler writes about the ways coaches use analytics, how much, how often and why. He examines how the numbers can have a positive impact and warns against overusing them.

The analytics movement in the NHL is growing, and coaches are on board, but the key is still about striking a balance between how often you use the numbers and how much information you give your players.
Using the numbers in a concise way can back up the message you are giving the players during video sessions and in practice. It provides another layer of information for coaches to give them.
On the flip side, using too many numbers, or using them too often, can be detrimental to your team's well-being.
The challenge of catering the numbers to your benefit in the regular season is to not get bogged down by looking at all the numbers after every single game. It's just too much to sift through. All coaches have an analytics package that they use for postgame analysis that provides a consistent read on what is important to them on a game-by-game basis, including chances for and against, and how each was generated. However, teams will dig a little deeper analytically at certain points of the season.
To get a broader idea of how their team is performing, coaches usually break the season into segments, whether it's 10 games or 15 games, and take a more advanced look into the numbers just so there is a body of work to look at. You'll hear coaches talk about their segments all the time. This is part of what they mean.
For example, we're at about 20 games for many NHL teams, and I'm guessing at the quarter mark a lot of teams will take another big picture look and ask, "Have we gotten better in this segment?" and "What are we really good at that we're not doing as well as we should be doing?"
The numbers will play a significant role in answering those questions, so the coaches know what they need to focus on, both collectively as a team and for their individual players for the next segment.
It's different in the Stanley Cup Playoffs, especially when you're going into a series. That's when you take a deeper dive and really dig into not only your team's identity but the other team's identity: Where do they have the most success? You rely more on the numbers to help you analyze your opponent than you do at any other point in the regular season.
However, you still can't focus on 15 things; you focus on two or three things where the other team is having success, and you always try to bolster your team and what it's doing well, and how you can expose the other team by what you do well.
For example, the Vegas Golden Knights track really well, meaning they backcheck well, so you're always thinking about playing more of a north-south game against them as opposed to playing an east-west game. They create a lot of turnovers in the neutral zone because they track back well and put so much pressure on the puck. You have to focus on playing with speed and pace but also be careful about playing too much lateral hockey.

Paul MacLean, another Coaches Room contributor, likened the use of analytics in the NHL today to the use of video clips two decades ago. That makes sense.
All the editing software has certainly made our job a lot easier and has allowed us to dig into a lot more information through video work. Analytics is doing the same and is becoming the norm, and the numbers are growing, especially with each team employing its own analytics department.
We're not talking about just one person; it's a team of people giving information to the coaching staff. The staff has to be able to break down the information, decipher it, then communicate the message to the team in a way that is clean and easy to understand. Players can't step onto the ice, in practice or games, trying to figure out what was just said in the meeting.
When I started coaching, you looked at scoring chances for, scoring chances against, shots against, and there were a few more. I worked for Ron Wilson, and he kept his own database of individual player and team stats, making him his own analytics person before all of this happened. Analytically, he was ahead of his time.
But just like when video was getting going, there were some coaches who were guilty of spending too much time in their office and not enough time in the dressing room, and the reverse was true as well. Your connection with your players is still the most important aspect of coaching. You have to find that balance because your relationship with your players can't get buried behind the numbers.
What the numbers should do is help you as the coach tell the story to your players and provide an exclamation point to the message your giving.
You're not just telling them what you think anymore. You're showing them hard numbers generated by a computer, and if it shows you need to be better at X, whatever that is, be it the forecheck, the rush or defending the rush, there's no debating it.
With today's players, it really hits home to them because they want to see that data, they want to know. Providing players with the right information is critical to your team's success.
The more answers they have to the why questions, the better off they're going to be.