Clutch Play, the Slipper Clutch
That's fine for the vast majority of street riders. But if you want to get the most out of your motorcycle, there's a whole another level of clutch play.
The first thing you need to do is make sure your clutch lever is adjusted correctly. You want the engagement point to fall comfortable within the reach of your hand, not too close or too far from the grip. On hydraulic clutches, simply change the setting on the levers thumbwheel adjuster; on cable clutches, vary the amount of free play at the lever or down by the actuator. Be sure not to completely eliminate the free play or the clutch may slip. Your owner's manual will tell you how much play is correct.
Once that's accomplished, start thinking about the clutch lever not as a toggle switch but as a rheostat with an infinite number of settings between on and off. Flash back to the mini-bike you rode as a kid. No matter how far you turned the throttle, the engine note barely changed as the rattly little centrifugal clutch slipped just enough to keep the engine in its powerband.
As anyone who's ever raced a 125 knows, you can do the same thing manually with the clutch lever. Try it the next time you get into a corner a gear too tall on your bike. Remember the parking-lot circle you had to negotiate while going for your motorcycle license. If you did it right, you set the throttle for a steady rpm and then slipped the clutch to make the arc as smooth as possible.
A good rider should be able to do circles with the handlebars at full lock and his feet on the pegs. Master this drill and everything else will seem easy. Slipper clutches have recently begun to trickle down from racebikes to streetbikes, minimizing the rear-wheel hop that sometimes occurs when downshifting a sportbike with a high-compression, light-flywheel engine. But racers were slipping the clutch on down-shifts long before these mechanical devices came into being; they just let out the lever slowly, holding the clutch shy of full engagement until they were ready to begin feeding in the power again.
This can be helpful whether you're tearing up the racetrack or riding cautiously in the rain. Learn to make use of these techniques and the next time one of your buddies starts bragging about his slipper clutch, you can do what we recently saw on top-lever racer do: Show him your left middle finger and say, "I got your slipper clutch right here!