One way to hold this phrase: a fenced stretch of land with hills, mud and deliberately terrible roads, where a new machine is driven until something on it breaks. Nobody goes there to get better at driving. They go there to find out the truth about the machine, early and . Everything else the phrase does is that same stretch of land, with the machine swapped for an idea, a business or a person.
One branch
把東西放進去，試出真相
兩個意思共用同一塊地的畫面。差別只在被送進去的是一台車，還是一個新做法、一個新人。
noun · C1
A large piece of land kept for testing machines and equipment — especially vehicles, and also weapons or military gear — under hard, real conditions, away from ordinary roads and towns.
試驗場