When is PlayCount incremented?

[HawkXP71 120]

Can the algorithm that increments the PlayCount be described?

I am seeing some very inaccurate numbers, but I cant for the life of me determine what triggers the increment.

Its not marking it played.  That much I know.
But its also not "watched from intro end to credit start"

Is it watching for more than 1 minute? 30 seconds? 10 minutes?

TIA

[Luke 43041]

Hi, it's as soon as you start playing.

[HawkXP71 120]

Just now, Luke said:

Hi, it's as soon as you start playing.

I havent seen that to be the case.  Is there a minimum number of seconds?