Question #3: How can we measure a player’s scoring ability?
Let’s define the Scoring Phase as all of a player’s turns where the first dart is thrown with a remaining score which cannot be reduced to zero with three darts. In other words, when a player throws the first dart of their turn knowing that there is no possibility of checking out, that entire turn counts as part of the Scoring Phase.
Much of the time we can find the scoring average for the first 9 darts and that’s frequently used to measure scoring ability. But is that number an accurate representation of the player’s performance during the scoring phase of the game? What if the player is still in the scoring phase beyond the first nine darts? What if they had a perfect start and are already on a checkout after 6 darts?
It’s not difficult to construct a scenario where a player scores well through 9 darts but then has a subpar visit before getting down to a finish (100-100-100-41). Here the first 9 average is 100. But after the fourth visit the average drops to 85.25. The opposite can happen as well. Maybe the player’s first visit is low, but they recover (41-100-100-100). Now the first 9 average is 80.3 instead of 100. The player in the first example didn’t really perform better during the scoring phase. They just happened to have their lower score come after the first nine darts. It’s hidden from the first 9 average and makes the first player appear to have a higher scoring average. In my mind those two examples should be exactly the same. In both cases the player’s Scoring Phase Average is 85.25. Every turn during the Scoring Phase should contribute to the scoring ability calculation. It shouldn’t matter if it takes nine darts or eighteen darts.
I propose using Scoring Phase Average to measure a player’s scoring ability. The Scoring Phase Average is simply the 3-dart average score of all darts thrown during the Scoring Phase.
Here are the Scoring Phase Average results along with the 9 Dart Averages for comparison from the first week of the 2018 Premier League in Dublin:
There’s not a huge difference in the two values, but the relative rankings can change significantly when going from one to the other. Wright’s First 9 average of 108.17 is better than van Gerwen, van Barneveld, and Suljovic, who all scored between 106 and 107. However, converting to the Scoring Phase Average moves Wright behind van Gerwen and Suljovic, and ahead of only van Barneveld. I believe the Scoring Phase Average is the more accurate measure and that on this night van Gerwen and Suljovic really did outperform Wright in the scoring phase of the game.