## In Praise of the Bumps Chart II

##### Jul 18, 2005

On the left is my beloved Bumps chart (Cambridge 2005 May Bumps). It has a perfect union of function and form.  Here are some salient features:

• The horizontal axis records time: the first and second columns of text display the starting and ending orders of the college boats.  The zigzagging lines delineate each boat's movement over the four days of the race.
• The vertical axis serves dual functions: it both gives the current ranking and maps to the physical location of the boats along the river.
• What we care about is the movement of a boat over the four days; what we really care about are boats that have moved a lot, either up or down. The chart manages to highlight precisely what we want to see: the larger the movement, the steeper the line, the more attention it gets from our eyes.
• Focusing on #10 and #11: the criss-crossing lines tell a rich story of tit-for-tat over four days, in which the boats exchanged bumps during the first three days, with the Jesus boat leading after day 4.
• The story at #1 (Caius) was altogether different: as "Head of the Cam", this strong boat eluded the chasing fleet all four days.
• My alma mater started and ended at #3 (Trinity Hall)

A truly spectacular chart can be produced by placing all the historical 4-day charts side-by-side, painting a rich history of the rise and fall of different boat clubs over decades.  If anyone has seen such a chart, please send it my way!

Kaiser,

This is a lovely commentary about the boat race chart. Its something I'd always just taken for granted but you're right it is very good at portraying the relevant information.

I'm sorry I don't have "the big" version you want but I'm sure it can't be too hard to track down.

Hi Kaiser!

nice bump statistics! I also would like to see the whole statistics and do some testing: Calculate the mean position of each team over all years and look whether it follows a normal distribution, as expected by a random process, or not. That would be fun.

and visit me in Berlin!

Felix

If I can get a hold of training schedules, weight of the boaties and so on, I can then answer the question of whether the success is due to skill, to hard work, or to pure luck! Wonder what Adam has to say about this...

Felix - Berlin is still on my list... I just need the dollar to strengthen some more

In my opinion, the chart would be improved if background colors were chosed to be more neutral (two greys, for instance), thus permitting choice of a wide number of colors for teams and their connecting lines. Just choose about 5 colors and use them cyclically down the right side. I suggest this as a way of making the job of tracking one team easier. The sufficiency test here is to remove the team names and see now much information is retained. Not much, I'm afraid, since there are many line junctures where the choice to follow the line up or down is completely ambiguous. Colors would largely eliminate the ambiguity.

To Kaiser: It's not really ambiguous. If you get to a 'junction' between lines - then you should simply continue to follow the straight line that you were on before you reached the junction. You aren't allowed to turn off at a junction.

Where the lines cross represents where the crews have changed places in the following day's order (following a bump).

Also, these charts have been taken from the 1st & 3rd Trinity Boat Club's website www.firstandthird.org Their club colours are dark blue & gold - the dark blue on these charts are similar to the website's background colour. Plain coloured charts are around - e.g. on Wikipedia. http://en.wikipedia.org/wiki/May_Bumps_2005.

There are large-scale charts around - but in the lower divisions, the crews involved may change (there is a qualification race held about 5 days before the main races to decide which crews gets to race in the bottom 10 spots in the main races). This complicates things somewhat and means that you can't just slot one year's charts directly next to the previous year's for all divisions. Tim Grainger has created an excellent compromise at http://www.mcshane.org/bumps/

It's interesting so see clubs which are growing in strength, or in decline. All clubs have bad years, but some have always stayed near to the top of the charts. In the men's races - 1st & 3rd Trinity have never been below 10th (1st Trinity before them never went below 8th), Lady Margaret (LMBC) never below 11th, Jesus never below 12th - all records maintained since the 1820s. Remarkable considering the huge turnover of personnel over that time. Many smaller clubs have had good years, but there are a good number which have never finished in 1st position.

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