How is loose packing different from tight packing?

"Loose packing" provided for a fewer amount of slaves per ship, in the hopes that it will result in a greater percentage of the "cargo" arriving at the location alive.

"Tight packing" was when more slaves, despite the odds of them arriving alive, would be "packed" in a ship-caused by the notion that it will be more efficient-as it will sell higher at the auction block.