Every group of woods are made with a different Bias. The bias is the curve of the wood. This means that there are many different ways a wood roll, some are very wide which suit the outdoor player and a very narrow bias which can be played both indoor and outdoor. Every player settles into one or the other but it takes time to establish where your skill lays.

Below are a few charts from each of the bowls woods manufacturers showing how each of the different make and model of woods roll.