Brilliant addition to the thread mate, I like it. My two questions would be this:-
1. What is the biggest number of points in the Premier League era a side has been relegated with? Would this be better than the 48 point line for reducing the clutter?
2. Looking purely at the graph, who would you be most worried about?
The answer to #2 for me is Palace, Swansea & West Brom. They both look the sides heading in just one direction (although Palace had one good result recently).
1. When I did my analysis last year, before we set up the Relegation APLT, I only went as far back as 2000. During that period West Ham were relegated in 2002/2003 with a points total of 42 (I've included the summary data I did back then below seeing as it might interest you). I suppose I could set that as my cutout point and therefore remove a couple of more teams, however drmick loves the clutter for some reason
Generally, I try to keep it as uncluttered as I can but also try and include all the teams that are in danger of being dragged into the relegation battle so that we can see their trends. It's a delicate balancing act considering that any team in the bottom 10 can easily jump into the bottom 3, especially at the moment. Maybe it was a bit too early to start it this year but as the season progresses hopefully I can drop some more teams out.
2. I see what you did in making your assessment: you visually mapped out trendlines for each of the teams and extrapolated, that way you can project those 3 dropping more than the others. In a way you're not far of the mark, the thing is, you have to be careful at this stage due to the par 0's.
Take Stoke for example (see
https://www.redandwhitekop.com/forum/index.php?topic=336191.msg15665847#msg15665847). A lot of their games were par 0's, 'bonus games' as I like to think of them. They don't impact on the RAPLT point system in a negative manner,
only positively. If you extrapolate with these in mind our perception is skewed. If you exclude these games (but only if no points are gained from them) then you have too small a sample set to make an informed decision. More games will be required to assess them and whether they are a cause for concern.
However taking that aside I would still tend to agree with you - based purely on the graph - that Palace, Swansea & West Brom's continual decline/slope so far does paint them as the ones to watch.