Referred to as knuckle busters, direct-drive reel handles spin when the fish escapes; antireverse handles remain stationary. But knuckles get busted because people crank incorrectly with a direct drive. You don't wind in large fish. Instead, you pump the rod to draw the fish near, and as the rod is lowered you wind in line. Realizing this, if you hold the handle by the tips of your thumb and first two fingers, you can easily recover line as the rod is lowered. If the fish bolts, the finger tips slip from the handle, and no injury results. That is why most direct-drive reels have a handle that is round and tapers - so the fingers can easily slip off.