Track historical data

[bvankat]

The updates.json file is now recording all of the scrapes.

• Let's compare the most recent scrape to the previous one and put a little green/red arrow next to the rankings to show up or down movement.
• Track in-season progress with a line chart on the page.

[bvankat]

Reminder: There's been a little progress on this already. "div.chart" is already on page. dot-plot.html has the beginnings of the charts, too.

[bvankat]

Is the cleanest way to do the up/down arrows to look back at the rankings before the most recent game? Then they'd be relevant for a few days, rather than just "yesterday's rankings".

So you'd have to:

• look at one of the sites to find the most recent completed game
• search the previous rankings for one that matches the day before that game
• math the differences between each ranking ... if it was calculated that time
• store the values in an array
• draw the arrow and "+/-5" based on the result if it's in the array

[bvankat]

A simpler way to do it would be to say "last 7 days" or "last 4 days" or some approximation of "most recent game" without having to actually find that game. "T-4 days" would be a lot easier to compile.