Snowfield Sinkhole

In Commander, Snowfield Sinkhole is a low-friction dual land for any Orzhov or multicolor deck that touches white and black — the enters-tapped cost is real but acceptable at 40-life pacing where you have room to spare a tempo turn early. In Pauper it's one of the better common duals available and sees legitimate play in Orzhov control and life-gain shells that need both colors without spending rare slots. Modern and Pioneer have access to faster untapped options, so Snowfield Sinkhole largely sits out of competitive contention there. Legacy and Vintage don't need it either — the fetch-shock manabase makes it obsolete. Play it in Commander and Pauper; skip it everywhere else.