Sunday, 22 September 2019

Bullet Charts Added to Golf Predictor

Season pane for F Molinari ahead of the 2019 BMW PGA Championship, showing 2 new bullet charts.

I am pleased to announce the addition of colourful new bullet charts to Golf Predictor. Bullet charts are a type of statistical chart that can be used to  show performance at a glance. I have adapted them for use with ranks (mostly field ranks, but also ranks for season and season segment data) in Golf Predictor, using the already available rank statistics on the various pages. This can be seen in the screenshot above of the Prediction Data page for Francesco Molinari ahead of the 2019 BMW PGA Championship.

There are several elements to a bullet chart:
  1. The chart is broken down into five colour coded ranges, from deep green to deep red, with values nearest the left hand side (green end) being better. Each region represents 20% of the entire chart range (see next point).
  2. The middle yellow range are average ranks and the entire chart range is the field size for the bullet charts on the Prediction Data page (varies from about 60 to over 200, depending on the event). For the bullet charts on other pages, the chart range is the total number of records (Season Segment Data) or number of records for that season (Season Segment Data).
  3. The horizontal gold line and vertical bar represent the actual rank for the player in question. The position of the vertical bar tells you immediately how good the rank is. As can be seen above, Molinari's rank for season average is in the top region (dark green), which is well inside the top 20% of the field. However, his rank for average finish in his last five events is not as impressive, being in the second region (lighter green).

Hovering over a coloured range on a bullet chart will tell you the top value (rank) for that range. Doing this on the right hand deep red range will tell you the entire chart range. Hovering over the horizontal gold line or vertical bar will show you the golfer rank. This is shown above for the last five events average rank for Molinari (36). This will be the same as the value shown in the relevant rank field on the page (can also be seen in the final data row above). Some notes on these new bullet charts:
    1. The bullet chart is hidden if the golfer has not played any relevant event and therefore does not have a rank for that metric.
    2. Some extremely good ranks may be difficult to see on the chart, especially when the entire chart range is large (i.e. Season Segment Data and Season Segment Data pages). This is because the horizontal gold line will be extremely short and you may only see the vertical gold line.
    3. These charts have been implemented using the same modestly sized JavaScript library as used for the box plots, so page performance should not be adversely affected. You may need to reload the library (press Ctrl+F5 on Windows) though, as I have amended the library slightly.

    There has been a total of eighteen new bullet charts added to the pages on the site that show statistical information on a golfer's results in a certain collection of tournaments. Specifically, the bullet plots have been added to the following pages:
    1. Season Data page (1 bullet chart for season results)
    2. Season Segment page (4 bullet charts for overall/early/mid/late season segment results)
    3. Prediction Data page (13 bullet charts for GP season/last five events/course/tournament/last twelve similar events/similar weather/similar length course results/region/field strength/season segment (same chart as shown in item 2)/DraftKings/PlayOn/strokes gained)

    This brings the total number of charts on the site crashing through the six hundred barrier to 604! I trust you will find these new bullet charts useful as a graphical representation of a golfer's performance in certain key areas relative to his peers. Just another way to make Golf Predictor even better!

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