How to Grip the Ball to Bowl Offspin
To grip the ball to bowl offspin, start by spreading the knuckles of your index and middle fingers across the seam so that the stripe runs between them. The seam of the ball should be horizontal, rather than vertical, in your hand. Allow the ball to gently rest against your ring finger to help support it. Then, tuck your thumb and pinkie finger to the side and be sure to keep them relaxed so your hand isn't rigid when you need to rotate it. As you release the ball, aim to bowl just outside of the off-stump.
Remove any sweat from your throwing hand before you grip the ball. A good grip is key to delivering a successful offspin bowl. To ensure that your fingers are able to hold the ball correctly, wipe your hands to remove any sweat and dirt that could cause the ball to slip from your grip. Use a towel or your shirt to wipe your hands. Hold the ball so that the seam runs horizontally. The standard way to hold the ball when you bowl is to line up the seam so that it runs vertically in your hand. To bowl offspin, you need to grip the ball so that the seam runs horizontally to help line up your fingers. Make sure the seam is lined up evenly so you can use it to help position your fingers. Spread the knuckles of your index and middle finger across the seam. Grip the ball with the top knuckle of your index and your middle finger on your bowling hand. Stretch them across the seam of the ball so that the stripe runs between them. Your middle and index fingers will be spread wide to allow you to hold the ball firmly. Rest the ball against your ring finger. Allow the ball to gently lie against your ring finger to help support it. Your fingers and wrist are what will generate the spin on the ball. The ring finger acts as structural support for your fingers. Don't wrap your palm around the ball or it will limit your ability to generate spin in your bowl. Tuck your thumb and pinkie finger to the side. Your thumb and pinkie finger are not involved in an offspin bowl and can actually get in the way of your delivery. To keep them out of the way, tuck them off to the side when you're gripping the ball. Keep your thumb and pinkie fingers relaxed so your hand isn't rigid when you need to rotate it. Line up diagonally to the left of the stumps. In order to spin the ball effectively, it's important that you position yourself correctly before you bowl. Take a starting position to the left of your stumps so you're standing diagonally to them to help align your bowl. Grip the ball in the correct position for an offspin as you line up your bowl. Take about a 5 step running start to the bowling crease. A running start will help you build up momentum to generate extra force that will improve the spin of your bowl. When you line yourself up, allow for enough room to take a running start. Start at a slow pace and build up speed as you approach the crease. Avoid stutter-stepping or hesitating or it could throw off the timing of your bowl. Aim your bowl to the outside left of the opposite stumps. The off-stump, or the stump furthest from the batsman is your target area. As you take your running start toward the bowling crease, aim to bowl the ball just outside of the off-stump so the ball will spin towards the batsman. Swing your bowling arm forward as you reach the bowling crease. While you're running towards the crease, you need to build up enough force to deliver your ball. Swing your bowling arm over your head to generate power. Be sure to maintain a good grip on the ball so it doesn't slip out of your hand before you want to release it. Turn your wrist and index finger to generate the spin on the ball. Roll your wrist forward over the top to turn the ball and cause it to spin. The turning of your wrist needs to be done at the same time that your bowling arm reaches the release point. Timing is key to a successfully delivered offspin bowl. Don't swing your arm in jerky motions. The bowl needs to be thrown smoothly. Release the ball at the top of your rotation. As you're swinging your bowling arm and turning your wrist and index finger, open your hand slightly to release the ball. Wait until the ball is at the top part of your throw so it goes where you aim. If you release the ball too early, it will fly straight up into the air. If you wait too long to release it, it will bounce on the ground before it reaches its intended target. Flick your index and middle finger as you release to add more torque. To add even more rotation to the bowl, as you're turning your wrist and index finger and releasing the ball, give a last-second flick to the ball with your index and middle finger. The flick needs to be quick and short so it doesn't alter the path of the ball. If you flick too hard, the ball is likely to bounce on the ground and spin out of bounds. 
Remove any sweat from your throwing hand before you grip the ball. Hold the ball so that the seam runs horizontally. Spread the knuckles of your index and middle finger across the seam. Rest the ball against your ring finger. Tuck your thumb and pinkie finger to the side. Line up diagonally to the left of the stumps. Take about a 5 step running start to the bowling crease. Aim your bowl to the outside left of the opposite stumps. Swing your bowling arm forward as you reach the bowling crease. Turn your wrist and index finger to generate the spin on the ball. Release the ball at the top of your rotation. Flick your index and middle finger as you release to add more torque. 