Blockading has definitely been an interesting one this year. It's a 20pt call that could definitely change the outcome of a match. I don't it has in any of ours yet this year, but it's a huge points swing.
The way it was called between BAE and Waterloo was indeed very different - and I don't think I could call either way explicitly "right" or "wrong."
We saw lots of 2 on 1 defense at both events, and one consistent thing when blockading calls were made were two robots, lined up one in front of the other, driving sideways across the field.
This is about the only arrangement I've seen where blockading calls were made *consistently*.
The video referenced above shows that arrangement from about 28s to 20s left:
http://watchfirstnow.com/archive3.php?id=62472516
There's been plenty of 2 on 1 defense where that arrangement never happens, and no blockading call is made:
http://www.youtube.com/watch?v=X3FMK...YdSlRb_rLXUTtM
It would be nice it we could define blockading a bit more concisely, but honestly, I'm not sure how.