EFFECT OF ZS ON PERFORMANCE
STARTING IN YOUR OWN END
This is obviously a bad thing. Whether you come onto the ice on the fly with the other team already in (or taking) your zone, or you come out for an own zone faceoff, it’s not favourite. The latter is easy to measure because NHL.com shows who was out on the ice for every faceoff and every goal.
If a 5v5 NHL shift starts in a team’s own end, and a 5v5 goal is scored within a minute, and ALL of the players, for both teams, are still on the ice from the faceoff, the team with the defensive draw has seen:
· 43 goals-for
· 90 goals-against
That’s a pretty big difference
IMPORTANCE OF ZONE START RATIO TO PERFORMANCE
A lost defensive zone faceoff costs a team approximately 0.25 shots on goal.
With six goals corresponding to approximately one win, that has a huge impact on a defenseman’s apparent value.
Indeed, the correlation between which zone a player starts in and the number of shots for and against his team while he’s on the ice are very highly-correlated
EFFECT OF ZONE STARTS
A team that has more offensive-zone starts than defensive has earned them; good zone starts aren't just handed down to the team by some suit.
The first thing I noticed is that the first shift only accounts for about 37% of the ice time following a faceoff at either end
Having a faceoff in the good zone helps your team out territorially.
this almost completely goes away once the first change happens.
EXPECTED SHOTS FOR AND AGAINST WITH DIFFERENT ZONE STARTS
A player’s Zone Start% has a pretty good correlation with their Corsi Number at 5v5, with a sizable chunk of the variance due to player skill and luck.
Shots-for/60 = (Offensive Zone Start Percentage * 0.1668) + 18.07
Shots-against/60 = (Offensive Zone Start Percentage * -0.137) + 33.643
ADJUSTING FOR ZONE STARTS
(Jan 2012)
how much of an effect does it have and how do we adjust for it?
After some length of time, any advantage (or disadvantage) one might get from starting in the offensive (or defensive) zone would be nullified.
any advantage (or disadvantage) a player gains because of their zone starts occurs during the first 10 seconds after an offensive or defensive face off. After that, only the players talent matters and there is no benefit to removing more data from our analysis
EFFECT OF ZONE STARTS ON GOAL SCORING
I have noticed that zone starts affect shots/fenwick/corsi somewhat significantly but do not affect goal data much.
Shots within 10 seconds of a faceoff don’t go in nearly as frequently as shots at any other time. the league-wide shooting 5v5 percentage in the 10 seconds after the faceoff is around 3% while it is almost 9% the rest of the time.
So, what does this mean? It means you can actually probably pretty much ignore zone starts if you are looking at goal data. Zone starts have very little influence on the rate at which goals are scored.
EFFECT OF ZONE STARTS ON CORSI/FENWICK AND SHOT PERCENT
(Feb 2012)
while a lot of shots are taken in the 10 seconds after the faceoff, very few of those shots end up as goals.
If you are doing a corsi/fenwick/shot/shooting percentage based analysis accounting for zone starts is really important because it can have significant impacts on these stats
ZONE STARTS AND SCORE EFFECTS
A coach is far more likely to deploy a player with offensive talent when behind (ie. When the team needs goals) then when ahead.
Likewise coaches will probably deploy players with defensive talent when ahead (ie. When the team needs to keep the other team from scoring).
EFFECT OF ZONE START ON DEFENSEMEN POSSESSION NUMBERS
· Defencemen seem far more likely to put up low Corsi seasons than high Corsi seasons. Despite getting all of those starts in the offensive zone, you’re still going to spend a significant chunk of time in your own end because defencemen only change going one way – towards the offensive zone.
· Even if you start in the offensive zone, unless your team keeps the puck there for an entire shift, you aren’t getting off the ice without the puck coming out and likely coming into your own end.
· I’m a believer that ZS matters, although I suspect that it hurts guys with a tough ZS more than it helps guys with an easier one.
THE VALUE OF A ZONE START
for every additional play that started in the Offensive Zone, the expected goal differential gained is 0.0055.
Another way to think of ZS is that the value of Zone Start per play is the same as that for the top players in the league. So moving the start of your shift from the Neutral Zone to the Offensive Zone (or similarly from the Defensive Zone to the Neutral Zone) is like taking replacing an average player with a top player in the league.
ZONE DEPLOYMENT OPTIMIZATION
face offs are about starting with possession. When you lose a defensive zone face off, you are at a large territorial advantage and you have given up possession to your opponent
What media members fail to mention, in regards to non-neutral zone face offs and possession, is that a significant non-zero chunk of the observed effect in these face offs is due to the natural territorial advantage
It can also lead to optimizing puck possession potential by deploying players in situations best suited for their skills.
ZONE STARTS, CORSI, AND THE PERCENTAGES
· I just haven’t seen any convincing evidence that zone starts would change a players CF% much more than 1-2% and for most players considering zone starts in player evaluation is not important.
· What the zone starts signify is a style of play. Players with a heavy defensive zone start bias are likely asked by the coach to play a defense first game and in many cases generating offense is not an important issue. The result is often a relatively minor deviation in a players CA/60 but a major deviation in a players CF/60 from the overall team stats.
· Ozone% is likely an indication of style of play, or at least an indicator of the main objective of the players on the ice, and we have seen that this can have a major impact on shot attempt rates
· Players with a heavy defensive zone start will generally have a positive impact on his teams save percentage and a negative impact on his teams shooting percentage.
· Conversely players with a heavier offensive zone start bias will generally have a positive impact on his teams shooting percentage and negative impact on his teams save percentage.
ZONE STARTS AND IMPACT ON PLAYERS STATISTICS
· At the micro level yes, the location of face offs impacts outcomes. On the macro or aggregate level they are minimal.
· The higher the offensive zone start percentage the higher the CF%.
· Zone starts don’t drive CF%, CF% drives zone starts.
· We need to think of zone starts more as a result, not a cause.
· shots drive where face offs occur, where face offs occur do not drive shots.
WHAT DRIVES PLAY RESULTS – SKILL, SYSTEMS, OR RANDOMNESS
Teams that are good in the offensive, defensive, or neutral zones are likely to remain good at play in those zones.
So teams have control over performance in these zones and their numbers over half-season sample sizes are largely the results of skill, not luck.
Teams do have the ability to drive possession in the offensive and defensive zone. This suggests highly that systems and coaches matter,
In other words, the average skater, when given 100 extra offensive zone starts over the course of a season, can be expected to score three more points than he otherwise would.
1) It certainly appears that you can pump up a player’s offensive stats with more offensive zone time. That is, it’s not simply that better offensive players get more OZone starts, but that the favourable zone starts do indeed affect a player’s point total.
EFFECT OF ZONE DEPLOYMENT ON SHOTS
(Aug 27, 2015)
We shall see that these effects are generally overstated, and that in any given year only a handful of players can be said to have markedly atypical deployments.
What is more interesting is that there is essentially no difference between neutral-zone or defensive-zone faceoffs;
these results suggest that defensive zone breakouts and gaining the offensive zone may be largely separate skills at the team level.
Even more interestingly, the separation shows that, like a faceoff, the first few seconds after an on-the-fly change are vitally important, and winning this particular puck battle is the difference between a shift with many shots in it (the dashed lines) and a shift spent almost entirely defending (the dotted and solid lines.
. IN very broad strokes, where and how you start your shift is your coaches’ decision; what you do with it is yours
Compared to the faceoff shifts, the on-the-fly shifts have shots at very early times,
Nevertheless, after around thirty seconds, all shift types see broadly similar shot rates, clustering around 50-70 shots per sixty minutes.
At season scales, for almost every regular player, zone starts don’t matter.
THE EFFECT OF ZONE STARTS ON ON-ICE SV%
There are two kinds of shifts that tend to result in a higher save percentage: defensive zone losses and neutral zone losses.
Generally defensive zone shift starts result in higher on-ice save percentages while offensive zone shift starts result in lower on-ice save percentages.
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