» Averaging Values that Correspond with the X Largest Values in a Dynamic Range

Problem:

Column A contains dates of recent basketball games.
Column B contains the number of points scored by a particular player during each game.
Whenever a new game is played, the relevant dates and scores are added to the sheet.
We want to create formulas that will average the most recent X number of scores for each value for X listed in column D. The formulas should automatically update whenever new data is added.

Solution:

Use the AVERAGE, IF, and LARGE functions in the following Array formula:
{=AVERAGE(IF($A$2:$A$65000>=LARGE($A$2:$A$65000,D2),$B$2:$B$65000))}