TeamCity building Git / GitHub pull requests

Third build is actually the most valuable — it's the result of pull request auto merge (merge that happens, when you press the button at github).

Your builds seem redundant. The more thrifty way to organize TeamCity builds of feature-branches in git is as follows:

1. Organize continuous integration of your refs/heads/master branch. 120 seconds poll is quite reasonable here.
2. Organize nightly-builds for every refs/heads/feature-name branches. As of my experience, only a few of the feature-branches require 120-seconds polling.

TeamCity 7.1 has a very nice feature to autotrigger feature-branches, so step (2) can be setup in a couple of clicks with a branch mask like refs/heads/feature-*.

There is no meaning in building pull requests since they will be covered by master builds.