For just three mana and sacrificing an artifact, Tinker lets you tutor any artifact in your deck directly onto the battlefield, which allows for things like a Turn 1 Blightsteel Colossus or God-Pharaoh's Statue or Bolas's Citadel, all of which are pretty close to unbeatable
Ain't no spotlight in town that ain't eyein' Kitt, and she dang glows in 'em
This is especially true for commander cube if you support dragons as they're making a bunch of dragons that are not red, adding more density to enable the 5c dragon deck that I keep trying to make a reality
Many other cards have been printed with altered versions of this ability, such as Vedalken Shackles, but Old Man of the Sea is the first
Being able to prevent damage to your creatures is good, and its even better when your commander has mana sinks built into them
Either as a last-ditch protection spell on defense or a finisher on offense, being able to windmill slam this for zero mana was certainly a huge play
