Marcelo explains to Gianni the idea of loosening an opponent's Half-Guard before passing: When you don't quite have ideal upper-body control, i.e. chest-to-chest with Under-Hook & Head Control, you can still work against your opponent's legs before arriving into better position for your pass. Make yourself more room to free your knee by applying your shin against your opponent's Half-Guard and prying your leg loose. This will help you find a strong placement for your foot on top of your opponent's knee for the Over/Under Pass once you've secured a more stable upper-body control over your opponent. Changing up the pace and how much effort you exert mid-transition can prove beneficial against strong opponent's who are expecting a more traditional approach in your timing.