In this post I show a bumps chart of the 2009 Kentucky Derby made with Excel. This was an incredibly exciting race, with the winner, Mind that Bird, moving from last place to 1st place in the last 1/4 mile. The bumps chart captures the horses positions at 6 posts during the race.
Introduction
Bump charts are an effective display technique to show changes in rankings over time periods. While watching the 2009 Kentucky Derby, I saw a horse come from way back in the pack to take the lead, passing the other horses as if they were standing still.
Bumps charts were the farthest thing from my mind during and after the race. When I saw the replay, I was even more impressed how Mind That Bird was able to win the race.
If you haven’t seen the race, here’s a link to a video replay that is well worth watching.
Why Make A Bump Chart?
Yes, the race was great. A 50:1 horse won in a major upset. But why make a bump chart of the race? Actually I had no thought of making the chart until I read Andrew Gellman’s post on the race. One of the comments, Jon Peltier, suggested a bumps chart as a way to display the horse positions through the race. That got me thinking , hey what a good idea. However, before I could get my hands on the data, Andrew made it clear that he was thinking of some other type of chart.
Not being a serious horse race fan, I didn’t know where to get the data, Google came through again, I found the horse positions at this link.
Here’s the 2009 Kentucky Derby bump chart.
This is a busy chart, however, it does show Mind That Bird’s incredible sprint after the 3/4 mile post.
5 responses so far ↓
Jessica Chapel / Railbird v2 - Mine That Bump // May 11, 2009 at 7:56 PM |
[...] Kentucky Derby bump chart, from Charts and Graphs: [...]
Andreas // May 6, 2009 at 5:39 AM |
I think “mind that Bird” should have a black line, and the others only grey… Love the chart by the way.
derek // May 6, 2009 at 4:00 AM |
Michael, for eliminating the confusion of colours, we mostly just eliminate the colours, and grey down every line but the one or two we are interested in. Sure, that means that you can’t see each individual line, but that’s not a feasible goal as far as I can see. To see any particular line, we can add controls in Excel to select just the horse(s) we want.
What I like about bumps charts is that the vertical space available for line labels is exactly the height needed to accommodate the label, no more and no less. The variation of the bumps chart where rank is replaced by a scalar measure is called a line chart
ggplot2: Bump Chart « Learning R // May 5, 2009 at 5:59 PM |
[...] May 6 tags: bumpchart, chart, excel, ggplot2, plot, R by learnr Charts & Graphs blog has posted a 2009 Kentucky Derby bump chart made in [...]
Michael Pierce // May 5, 2009 at 4:55 PM |
Very interesting. Although most of it looks like spaghetti, it clearly shows the dramatic path taken by Mine That Bird to win.
Two thoughts come to mind:
(1) With this many data series, it’s hard to come up with distinctive colors for each horse in the field. Does anyone have any good strategies for presenting this more clearly? Especially in the middle of the race, the grays/blues/greens tend to muddle together too much for me.
(2) Would it be possible to show the distance between horses at each marker? I think this would help show not just the number of positions Mine That Bird crossed but the distance as well. For example, at the end of the race Mine That Bird was 6 3/4 lengths ahead of second position at the finish (as opposed to being 12 lengths behind the lead at the 3/4 mark). If each position had a distance as well along the vertical axis, it would show how much movement occurred as well.