winner-take-all

adjective3

1. •
   Of or pertaining to a contest, election, or other competition in which only the winner is rewarded and none of the losers receive anything.

   • You need luck in poker tournaments, because in the nature of this winner-take-all style of play, there will be several occasions when you cannot avoid putting all your money in the pot. — 1993
2. •
   Of a market in which a product or service that is only slightly better than its competitors receives a disproportionately large share of revenue.
3. •
   Of a neural network model: organized so that neurons in a layer compete with each other for activation.