I introduced my attempt to place values on plays using their success-rates in a previous post. That post include Expected goal values and expected shot values that were based on the average success-rates of Habs forwards for all succeeding events.
In an attempt to calculate the expected goal value of a series of puck-possession plays in the offensive-zone, this post will attempt to incorporate the success-rates of potential linemates for all succeeding plays. In order to link players, I incorporated who each player spent the most ice-time with last season, as well as where those players might fit into the upcoming season's lineup.
Not surprisingly, the Habs top offensive-players were consistently among the top EGV producers for each offensive-zone puck-possession play. The line of Max Pacioretty, David Desharnais, and Brendan Gallagher had at least one player among the leaders in each graph included below.
Every possession play that occurs on the ice has both an expected goal value (EGV) and an expected shot value (ESV). The goal value is represented by the chance of that specific puck-possession play eventually producing a goal. The shot value is the chance of that specific play eventually producing a shot on net.
Expected goal and shot value can be calculated by using the success-rate of that specific play, as well as the success-rates of all succeeding plays. The goal of this is to determine how successful that play has been to either produce a shot-on-net, or a goal.
Conditional Probability
For example, we know that for a pass to the slot to result in a shot, the player passing the puck to the slot has to be able to succeed with his pass. Also, the player receiving the pass has to be able to get his shot through to the net.
Using 100 attempts (to simplify the explanation), if David Desharnais is successful with 39% (tops among forwards) of his attempted passes to the slot, we know that the player receiving the pass will have 39 shot attempts as a result of those 100 passes (100*0.39=39).
If the player taking the shot is Max Pacioretty, and he has been able to get 53% of his attempted shots through to the net, we can then calculate the expected shot value of that initial pass by calculating how many of those 38 attempted shots would result in a shot-on-net (0.53*39=20.67). This tells us that a pass to the slot from Desharnias to the Pacioretty has an expected shot value of 20.67; as it has succeeded in the past at a rate of 20.67%.
The expected goal value would be calculated using Desharnais pass to the slot success-rate combined with Pacioretty's true-shooting-percentage (percentage of attempted shots that result in a goal). For example, Pacioretty's TSP was 6.6% (0.066*39=2.57). So a pass to the slot from Desharnais to Pacioretty has an EGV of 2.57, as that play was successful in the past at a rate of 2.57%.
This system will allow us to potentially determine the goal or shot value of any play on the ice. The key is to include every potential succeeding play as well.
EXPECTED GOAL VALUE (EGV) OF A PASS TO THE SHOT
The numbers communicated in this graph simply represent the percentage of all attempted shots from each player that resulted in a goal. Dale Weise's TSP (true shooting percentage) was impacted by a smaller sample size. As such, I avoided using his TSP in other players' expected goal values, knowing full well that his outlying success-rate would skew the numbers.
EXPECTED GOAL VALUE (EGV) OF A PASS TO THE SLOT
Not surprisingly, the three Habs centres had the top expected goal values for attempted passes to the slot. It's important to remember that the EGV is not only dependant on the success-rate of the initial play (pass to the slot in this case), it is also dependant on the player receiving the pass' true shooting percentage (goals scored divided by attempted shots).
Tomas Plekanec's EGV for a pass to the slot was calculated using Brandon Prust's TSP, while Desharnais' was linked to Max Pacioretty's TSP, and Lars Eller's was linked to Alex Galchenyuk.
EXPECTED GOAL VALUE (EGV) OF A CYCLES PASS FOLLOWED BY A PASS TO THE SLOT
Brendan Gallagher, Tomas Plekanec, Rene Bourque, and Michael Bournival had the top EGV for an attempted cycle pass in the offensive-zone. Gallagher's cycle pass was linked to a pass to the slot from Desharnais, followed by a shot from Pacioretty.
EXPECTED GOAL VALUE (EGV) OF AN EAST/WEST PASS FOLLOWED BY A SHOT
Tomas Plekanec and Brendan Gallagher had the to EGV for an attempted east/west pass in the offensive-zone. Plekanec's EGV was linked to a shot from Brandon Prust, while Gallgher's was linked to a shot from Pacioretty.
EXPECTED GOAL VALUE (EGV) OF AN EAST/WEST PASS FOLLOWED BY A PASS TO THE SLOT
Gallagher, Plekanec, and Desharnais had the top EGV for an east/west pass, followed by a pass to the slot and shot on net. Gallagher's EGV was linked to a pass to the slot from Desharnais and a shot from Pacioretty. Plekanec's was linked to a pass to the slot from Bourque, and a shot from Prust, while Desharnais' was linked to a pass to the slot from Gallagher and a shot from Pacioretty.
EXPECTED GOAL VALUE (EGV) OF AN OPEN-ICE DEKE FOLLOWED BY A SHOT
Dale Weise's EGV within this metric is impacted by a smaller sample size. Among those players with more significant sample sizes, Desharnais and Pacioretty had the top EGV for an open-ice deke in the offensive-zone, followed by an attempted shot on net. No linemates were used in calculating these EGV's, as no other player was involved in the play.
EXPECTED GOAL VALUE (EGV) OF AN OPEN-ICE DEKE FOLLOWED BY A SHOT
Desharnais, Plekanec, Gallagher, and Bournival produced the top EGV for a wall-deke in the offensive-zone. Desharnais' EGV was calculated using Pacioretty as the shot-taker. Plekanec's EGV was linked to Prust, Gallagher's to Pacioretty, and Bournival's to Plekanec's.
