Material imbalances game
Sacrificing two bishop for a rook ? A queen against knight and rook and a few pawn ? Do you ever do that ?
Unless you were born as a chess prodigy, you will need some study and or praxis of such material imbalances.
Here's a game where I deliberately did choose for a material imbalance, because I thought it gave me an interesting game and winning chances.
"You'll never know unless you try !" 
Maybe interesting to read :
 Mei Ling to Crane in one of the KungFu Panda videos about whether or not to train and join a contest.