[Amps] triode vs tetrode

[Joe]

OK like a 3-500Z, 3CX bla bla bla etc. are triodes, plate, grid, and 
well filament.

Most of these tubes run grounded grid correct? so the grid is simply 
grounded.

Now the 4CX bla bla bla is plate, screen, grid, and whatever filament etc.

What would happen if you simply wired it up like  triode in grounded 
grid. ground both the screen and the grid,  has anyone ever tried that?

Joe WB9SBD