Sharing a few of my own lessons from recent competitions in case someone finds them useful...
I've heard it before: if your dog is going up a wall and not finding anything, LOOK BEHIND YOU. But I've never experienced it before. An otherwise lovely NW2 Exterior search, until we literally hit the wall. I did not even SEE the spotlight in the ground behind us until the very end... and then was so fixated on the wall that I didn't listen when Buzz alerted on it, even though I'm the one that pointed it out to her!
In that regard, consider getting a LidCam to video your searches. I was waiting for Buzz to give me an indication that she had finished and found the hide (not necessarily a look back.) When she didn't we ran out of time, so I decided to review all of her competition videos to wrap my head around a few things. First, I confirmed that the only time she ever actually sniffs something, she's on odor and trying to solve the problem. And second, I discovered that when she sniffs a specific spot and doesn't give me an indication within five seconds, she's at source 100% of the time, so I can safely call the alert even though she's continuing to explore the dog spit or treat crumbs, or whatever else might be paired with source.
Wind Direction
Nose work peeps: Here’s a great example of how building influence wind direction. Watch how many different directions the wind blows the snow flakes….