R&R sells a bubble level for straight pins, dont ever know how I set cups straight before I started using it,lol....perfect vertical is what I strive for

Perpendicular to the Horizon, NOT to the Slope of the Green

Always set it straight...but this video to be honest is outdated... this meant for clay push up greens with sand build up from top dressing applications. Most greens are being rebuilt to meet new usga specifications. The rootzone is 12 inches of 90% sand and 10% peat. No makes clay greens anymore unless where they grow fescue greens but even than sand is best for drainage

​@@apaulmcdonough2170 yep always straight in the air. Cups are never set on huge slopes it's impossible and makes play way to long, setting close to slopes is the right way, stuff hard but not impossible