Hockey Stats: What Top Coaches are Looking At
Over the past two weeks I have written about the collection, generation and use of stats in hockey. We have moved from rudimentary statistics that can be found on the game sheet to more advance statistics that need a person or two tracking stats in the stands during the game - or at least video analysis in order to see the game again a second or third time.
Here are a few more stats that, through conversations (and replies to my post last week), seem to be helping coaches make decisions about their team and their players:
1) One reply to my blog post last week pointed to an interesting article at mremis.ca. In the article entitled Green Shots & Red Shots: How Steve Valiquette is discovering which plays are most likely to score, Michael Remis writes about the “Royal Road” (a line down the middle of the ice from net to net) and scoring percentages:
Operating on the basis that not all shots are equal, Steve Valiquette has categorized shots as green or red. Green shots go in the net 76% of the time, red shots make up the other 24% of goals. Different types of green shots are as follows:
Passes across the “Royal Road”
Players carrying the puck across the “Royal Road”
One timers on the same side of the “Royal Road” (either side, left or right)
“Those sequences are all qualified by the fact the goalie has less than half of a second of sight before the puck releases from the shooters stick.”
The following types of shots are when a goalie has more than half a second of clean sight of the puck. They are categorized as red shots. They are:
A player walking from the corner jamming the puck to the net
A player coming off the rush, where a goalie sees the puck and there’s no screen
This is a great article, particularly if you are looking at goalies and their performance. With regards to players and scoring, especially at the non-NHL level, strength of shot needs to be factored into this equation and keeping record of how the ”green” shots break down would be very helpful (i.e. how many screens, deflections, passes across the “Royal Road”, etc.).
2) Tracking positive and negative puck touches. A time consuming endeavour for sure but, tracking whether a player makes a positive play with the puck or not can certainly determine whether a player, line or a team has had a good game. One Canadian men’s university team in the early 2000’s tracked this for an entire season and found a correlation between this and winning hockey games. Typically, the way they tracked, a good game would be in the >70% positive neighbourhood and usually translated into a win. Below 70% was considered a not so good game and typically translated into a loss.
I also remember one coach telling about using this statistic to make a final player selection for a team. They had played a number of exhibition games and two defencemen were deadlocked for the last spot on the roster. It seemed like nothing could separate them on the scouting reports from the stands. The video coach then looked at all the players’ touches for the exhibition series and found one player’s positive touch percentage to be more than 15% points higher - something that wasn’t readily observable from the bench or the stands. It turned into a great use of advanced stats to help a coach with decision making.
3) Zone Entries and Exits. Another area where coaches are finding advance stats tracking useful is in charting how teams get the puck over the blue lines. Statistics track whether the exit or entry is controlled, dumped or failed. Again this stat can be tracked individually, as a line or as a team. As a secondary analysis, this same statistic can be tracked in correlation to individual puck touches. For instance, a team can track the success rate of a controlled zone exit when a particular defenceman has touched the puck in the sequence. (You could track a goalie in this regards as well on goalie touches.)
All of these stats are tracking team and individual performance but not necessarily looking at the opposition. There are a few pre-scouting stats that have become very valuable to coaches in both pre-game preparation and bench management. In particular, who the opposition uses on certain faceoffs in certain zones, who they put on the ice after special team units, how the opposition gives up scoring chances and how they create them.
Statistics can be a terrific help in making decisions. As a coaching staff, there needs to be a balance between what is genuinely worth the time and effort it takes to track, generate and analyze all of the events that happen so quickly in the course of a hockey game and how useful it is to understanding your team and the opposition.