An upward spike in an album, artist, or track's weight generally indicates that the object in question's last_queued just got pushed a good ways further out, as compared to it's competitors. For example, imagine if the second ranked track has a normalized last_queued value of 0.8, while the first ranked track has an (obviously) normalized last_queued value of 1.0. When that first ranked track gets played, the new first ranked track goes from a value of 0.8 to 1.0, which is a jump of 0.2, and could look significant on one of these graphs.
If a track is played from the same album as one of the tracer tracks, we expect to see both the artist, and the album graphs dip. The track graph should remain the same however.
When a track by the same artist, but from a different album as a tracer track is played, we expect to see the artist graph dip, but the album and track graphs should remain the same.
The track average should move slightly with time. This represents the distribution of the last_queued times as they fluctuate. While the track ratings obviously don't change (at least not in a test environment), the last_queued times can clump up and spread out.
Fire It Up
was not chosen at random, like the other
tracks. It was chosen because it gets played. A lot. Too
much. I want to study it some. I believe the reason it gets played so
much is that it is the only track, on the only album I own by the
Kottonmouth Kings. The rest of the album is so terrible I disabled it.
Hence, Fire it up
is the only track that can be played from that
album. I think that's why it gets played so much. It makes
sense at any rate. Solution might be to penalize tracks that are on
albums with disabled tracks.
If you're not me, you might be wondering what Max Track and Chunk are.
Max Track is the weight of whichever track in the system has the highest
weight. The actual track represented by Max Track can, and does change
very often. It is a Virtual Track
so to speak.
Chunk is a randomization feature. To choose the next track, weights are calculated, and any track whose weight is within Chunk of the Max Track, is eligible for selection. So if you're a track, and your weight is greater than or equal to (Max Track's weight - Chunk), you're in the running. As you can see, getting above the Chunk is by no means a guarantee of being played. Chances are, a few other tracks from your album are there with you, and you all have an equal chance of being picked. If your albummate gets picked, your weight will plummet due to penalties to both the album and artist portions of your weight.
If a track seems to tank to an extremely negative value, that indicates
that the track is not eligible for queueing under the current schedule.
For example, Alpha Omega
is on an industrial album, and as such
is not included in the Hip Hop mood. When the Hip Hop mood is being
played, Alpha Omega
is not eligible to be queued, and so will
display as an extremely negative value.