What are captains looking for in the pitch when they have to decide to bat or bowl first if they win the toss?

Hi Steven, great question...

Sometimes I wonder if they know too ;-)

From my understanding, they would want to know from the groundsman what preparation was done on the wicket. This would allow them to estimate what characteristics the wicket would or could have.

Armed with that information they would look and feel the pitch.

They would look and feel for the hardness (how much the clay has been compressed) of the wicket, harder wickets tend to be quicker. Softer wickets tend to be slower. (Think England)

They would look for and feel the moisture in the wicket, the length of grass and grass coverage.

All these and possibly some more factors affect how the wicket will play. They use this information along with venue history, to make an estimated guess on batting first or second.

Hope this shines a bit of light on the question. Am sure I have missed some things ;-)