Originally Posted by
CDu
Correct. Similarly, the spurt of offense by Illinois near the end of the half can skew the data as well. Sometimes the opponent just catches a few breaks, and sometimes the opponent happens to hit a few shots that they weren't hitting at other times. Good defense doesn't always result in good outcomes, and bad defense doesn't always result in bad outcomes. Because of this, it's hard to tell whether the +/- indicate a causal effect of a player or a coincidental result when the sample size is just one game.
These issues do tend to wash out (somewhat) with a larger sample size, so I hope the +/- is summed over the course of the season. It will be very interesting to see those numbers. If used correctly, they can be a very valuable tool for evaluating an individual player or particular lineup with respect to their value to the team.