Expanding ETS(1/2) at the final step to show the geometric weight on every past observation — the most recent gets half, then a quarter, an eighth, and so on.
highlighted = computed this step
Weight contributions at final step
The smoothed value is a weighted sum of all past observations. Weights decay geometrically — the most recent observation carries the highest weight.
weight table
Geometric weight decay (bar plot)
The weight on each past observation halves with each additional step back. The initial observation absorbs the remaining tail weight.