Most played cards in Mono Black Control:

1 Decks
Deathmark
4 copies - 4 average
Smother
4 copies - 4 average
Phyrexian Arena
4 copies - 4 average
Hypnotic Specter
4 copies - 4 average
Blinkmoth Nexus
4 copies - 4 average
Chrome Mox
4 copies - 4 average
Death Cloud
4 copies - 4 average
Hideous Laughter
3 copies - 3 average
Umezawa's Jitte
3 copies - 3 average
Offalsnout
3 copies - 3 average
Tombstalker
3 copies - 3 average
Solemn Simulacrum
3 copies - 3 average
Guardian Idol
3 copies - 3 average
Smallpox
3 copies - 3 average
Trinisphere
2 copies - 2 average
Cranial Extraction
2 copies - 2 average
Mind Sludge
2 copies - 2 average
Tendrils of Corruption
1 copies - 1 average
Oona, Queen of the Fae
1 copies - 1 average
Urborg, Tomb of Yawgmoth
1 copies - 1 average