Watching the recent ADCC-rules superfight between Kit Dale and Tommy Langaker there were two great guard passing moments. Let's look at them below. 

First off, here's the full match, which I recommend watching. It's an interesting clash of styles: Langaker was active with his guard and constantly hunting for an opening, while Dale played more conservatively and stuck to a smart strategy. 

In the first guard pass attempt– which takes place at 5.56– Tommy (bottom) is playing seated guard. They go into an under-over clinch position, and Kit redirects Tommy's right knee to the inside as he pops up and looks to punch his right underhook to the mat. 

So why did it fail? Tommy was able to bring his right shin inside before Kit's hips made it through the gap. This saved him and allowed him to bring the other hook inside. 

Next time, Kit makes an adjustment that kills that...

Same deal: from the under-over clinch position from seated guard. Kit goes for the pass on the same side. 

Instead of pushing Tommy's knee to the inside to go around, this time he pushes it down and goes for a standard knee-cut pass. Kit gets his hips in deep and low, which kills Tommy's guard recovery. 

High level stuff. Goes to show how minute adjustments have huge ramifications at the highest level. The guard pass was the deciding moment that won Dale the match. 

If you want to hear from Kit himself check out his narrated breakdown of the entire match.