Winner Nicholas Howe (Rapid Weight Loss May Be Harmful)

Darkness 2011-04-13 12:00:00 UTC

 

Twilight 2011-04-14 12:00:00 UTC

 

Daylight 2011-04-15 12:00:00 UTC

 

Finish 2011-04-20 12:00:00 UTC

Crossword - Statistics

This page was generated on 21-Apr-2011 at 3:20 PM ET.

1000 Node Challenge

These are the best entries submitted before 19-Apr-2011 16:00:00 that are less than or equal to 1000 nodes in length.

Saturday Leap

This listing shows how much each entry that took the lead on Saturday improved on the previous top score.

Best Per Phase

The top 25 contestant's best entry in each phase.

Top contestants during darkness

Top contestants during twilight

Contributions in Daylight

This listing shows how much each contestant improved on the top score over the course of the day.

Friday

Saturday

Sunday

Monday

Tuesday

Wednesday

Best Result

These are the first entries to break through each result barrier, ignoring time.

All the Leaders

Here is a chronological list of the entries that held the number one spot, listed with the date submitted, the percent improvement in score, and the length of time each spent on top.

Score

This is the most useful diagram for visualizing the contest. It shows the dramatic improvements that occur over time. Each passing entry is a dot, with its submission time on the x-axis and it's score on the y-axis. Since a lower score is better, the dots push down further as time goes on. All entries that took the lead are colored red and the red lines marks the best score at any time. The sample entry is the leftmost red dot and the leader is the last red dot in the lower right.

Some of the leading entries are circled and labeled with the author's name. They show who was making the biggest improvements in score (represented in this plot as a vertical drop in the red line) at any point in the contest.

The improvement in score happens over a huge dynamic range. Early in the contest, it is easy to make big improvements in the score. As the algorithms get better, improvements become increasingly difficult. To show this, we normalize the scores so the best (smallest) score is 1 and the worst score is some power of 10. Then we plot them on a logarithmic scale. This exaggerates the improvements at the end of the contest. By increasing the number of decades we spread the scores over, we increasingly exaggerate the smaller improvements made at the end of the contest.

results vs. cpu time

One of the interesting aspects of the contest is that entries needed to minimize two things at once. Getting the best possible answer must be weighed against the time an entry takes to run. The entry's score is a combination of these two factors. Plotting these two against each other yields a very different picture of the contest.

The leader line is shown in red again in this picture. The gray contours show lines of constant score. In general, the best score is somewhere along the lower-left frontier of shortest time and lowest results. Algorithmic improvements tend to move down and to the right, and they are followed by tweaking battles in which the new algorithm claws its way back down the time axis.

Submissions Over Time

This area plot shows how the total number of entries grows. The green area represents the entries that passed the test suite, and the red area shows those that failed.

Activity by Hour

Each bar represents an hour's worth of entries. The contest has three major phases. The first day is in "darkness", where contestants can submit entries but they can't see any of the entries or their scores. To win this phase, an entry must be general and robust. The second day is "twilight", where we show the scores but not yet the code. This allows contestants to develop their algorithm without anyone else being able to leverage their ideas.

On the histogram, the darkness and twilight phases are the two boxes on the left. The other boxes and vertical gray lines call out other mid-contest challenges.

Participants per Day

We know that one participant may submit hundreds of entries. Let's look at the number of unique participants on each day of the contest.

Most active participants

This bar plot shows the number of entries submitted by our most prolific authors.

Entry length

This plot shows how many characters of code are in each of the leading entries. In regions where you see entries of more or less the same length there are very few differences from one entry to the next. In other places you can see the code getting shorter or longer. The density of the lines also shows how often the lead is changing. It's most impressive when shorter code takes the top spot, either by pruning unneeded computation or by introducing new algorithms. The red line at the top shows the cap on entry length.

Percent improvement

This is a plot of the percent improvement generated by each new leader relative to the previous leader. This lets us see who is responsible for the biggest changes over the contest. The upper frontier of this plot is a sort of hall of fame, and someone whose name appears there more than once managed to make several significant improvements to the score.

Improvements by day

Highlighting all the entries submitted on each day in red shows shows how the overall progression down and to the left. A black circle indicates the leader at the end of each day.