January 3, 2020
|Name||OEFF||DEFF||EFF||Points||+/-||Time on Ice||Seconds on Ice|
Effectiveness (EFF) attempts to determine how effective a player is on the ice. Effectiveness is defined (for the purposes of this metric) as the player’s ability to help his team win a game. Effectiveness takes into consideration Time-On-Ice, Points (in the case of OEFF), and Plus/Minus. The formulas are simple, and I feel that after taking a look at how the numbers fall, it pretty much makes sense.
OEFF is determined by adding the player’s points with their plus/minus and dividing the sum by the seconds-on-ice. I multiply this number by 1000 for readability.
OEFF = (points + plus-minus) / seconds on ice
DEFF is even simpler to calculate as we simply remove the benefit of offense from the OEFF. This is also multiplied by 1000 for readability.
DEFF = plus-minus / seconds on ice
To determine a player’s overall effectiveness, we simply add OEFF and DEFF.
EFF = OEFF + DEFF
Line of Thinking
While this may seem like an off-brand points per minute, the focus is not on productivity, but on effectiveness. While the player is deployed, is he more or less likely to help the team win? The higher the EFF, the more likely they are effective. Players with an EFF under 0 can be considered ineffective.
The purpose in combining points and plus/minus in OEFF, is because I want to understand plus/minus in a meaningful way. Certainly, players are “doubling up” if they score a point vs just standing on the blue line when a goal is scored, but scoring a goal is in-fact more effective in helping one’s team win than not. Being on the ice, moreso than being on the bench.
In DEFF, we only consider plus/minus vs seconds on ice. Are goals scored against the team when this player is deployed? Many “fancy stats” measure the quality of a player very well, but DEFF aims to measure how effective they are at not allowing the opponents to score. Again, this is a measurement of effectiveness, not skill.
But Why? Why Plus/Minus?
I wanted to find a value for plus/minus, as it’s often derided in this modern analytics age. It’s my stance that while a lot of external factors go into plus/minus (deployment, quality of competition, goalies, zone starts, etc, etc), it does still tell a story about liability. Undoubtedly, a player with a high rating is doing something right, even if they are seeing more beneficial match-ups or zone starts. A coach only deploys effective players in those situations. Likewise, if a player has a low-rating, they may end up playing less, and scoring less points to offset their rating.