How to read this build status trend?

Hi

In the image below, how shall I read this Status Trend? There are four bars, click each of them, the build result page will change. Questions:
1. What does these four bars map to? Why there is four not five?
2. What does that red mean?
3. When I click the green bar, Logs: 5 logs. When I click the red bar, it displays Logs: 4 logs. Why?

http://i54.tinypic.com/11ccluh.png

Hi,

1. The bars map to your previous builds for that build definition. You have four bars because you have four builds for that build definition. It's a visual cue to give you an idea of the trend of your builds. If you are consistently running with many red builds then something needs to be fixed.
2. Green means the build passed versus red for a failed build. The red/green colors often get used in agile development terminology.
3. It could be that since the build failed that it didn't get to the step in your build where the final log is contributed.

Brent Ulbricht
RTC Build Lead