Roles and craft
Wicketkeeper
The fielder behind the stumps who takes catches, stumpings and every ball the batter misses. Modern sides expect the keeper to bat, too.
The wicketkeeper is the fielder who stands behind the stumps, catches everything the batter misses, and effects stumpings and run-outs.
Only the keeper may wear gloves. Standing up to the stumps against spin and slower bowling, they take the stumping when a batter drifts out of the crease; standing back to pace, they are the first slip that never moves. Byes are their responsibility, and a keeper who lets through a dozen a match is costing runs as surely as a wayward bowler. Every side needs one, and there is only one, which makes the position a selection problem of its own.
The modern debate is about the bat. A generation ago a keeper was picked for glovework and batted at seven or eight. Now most sides want a keeper who is also a top-six or top-seven batter, because that is what lets a captain fit an extra bowler or all-rounder into the XI. Managers weigh a few dropped chances against thirty extra runs an innings, and in limited-overs cricket the runs usually win.
In Masterstroke: your wicketkeeper is one of the nine fielders you place, and his batting rating decides how deep your batting order really goes.