Predators...what was it about?

The last Predatir movie made a few years back..I watched it once and then again a few months later but I don't remember what the main plot was..anyone care to refresh my memory? This is what I remember

8-9 criminals or military or mafia guys are sent to this planet..they get chased by I think predators hunting dogs of sone sort..?

Then I remember there being a few different predators and I think the predators were actually hunting each other too? I forget why

I remember the Japanese Samurai guy fighting a predator in a field lol

Oh and There's that black guy hiding out on a ship...

Judging by this I don't think it was that good of a movie