You do not need to master them all, and it is certainly not necessary to accumulate a large collection of different rakes. You'll need to be careful not to disturb the long pin when you push the short pin up. Note that these locks have been deliberately pinned with a short pin behind a long one. Tubular cylinders typically have four to eight pin tumblers arranged in a circular pattern around the circumference of the plug. In a lock with six pin stacks with a uniform chance of a pin setting at either shear line, the probability of a picked lock actually opening is only 1/64. Picking techniques for these locks involve the use of special torque tools designed to put torque on only one of the two concentric plugs. An important skill when picking is to recognize when this has happened so you don't waste time before you start over.

Gradually ease up on the torque, allowing pins to drop one at a time. When a foul is committed, the opposing player is awarded ball in hand, allowing them to place the cue ball anywhere on the table for their next shot. Each player attempts to outscore their opponent and reach the previously agreed-upon total required to win the match using a different colored cue ball. The player must first pocket a red ball and then try to pocket any colour he may choose, scoring the value of the ball that he has pocketed. Scoring a carom also entitles the player to another shot, and his turn, or inning, continues until he misses, when it becomes his opponent’s turn. In play, the object is to stroke the cue ball so that it hits the two object balls in succession, scoring a carom, or billiard, which counts one point. Developing successive scoring strokes is a necessary skill. Vary the amount of lifting between strokes but do not force the pins, lest you overset them. As the peaks hit the pin stacks, energy is transferred from the bottom pins to the top pins, much like the action of the cue ball in billiards.

Taking a jump shot Making a push stroke causes a ball to be forced off the table. It may be inferred that it developed from a variety of games in which propelling a ball was a main feature. A variety of schemes are used to key the sidebar. Russian Pyramid is a different portable game well-liked in the former Eastern Bloc, as are its variants like Kaisa. When the pin stack truly sets at the shear line, it will feel like an ordinary set pin. The usual scheme for master keying involves using more than one cut in some or all pin stacks (this is accomplished by adding additional pin segments). The Primus sidebar is keyed by additional side tumblers that engage a secondary bitting cut into the side of the key. In fact, master keyed pin stacks are easier to pick than those that are single-keyed; there are two chances to lift a cut to the shear line. The most common security pins are the "spool" and "mushroom" top pin designs, which are thinner in their mid-section. This may be a consequence of more stringent European insurance standards for physical security.

Mechanical combination locks are common on inexpensive padlocks, safe locks, and to control access to high security vaults. If only serrated top pins are used, reverse picking may be successful. If serrated bottom pins are used as well (as they are in, e.g., certain American brand padlocks), snap guns, bump keys, or sawtooth raking are likely the only picking techniques that will succeed, What is billiards especially for the novice. So far, we've been picking locks "a pin at a time," with a single pin stack set at the shear line in the sequence dictated by whatever misalignments are present in the cylinder. First, apply light torque (as you practiced in the previous exercises) to the two pin cylinder and gently feel each pin. When the final (non-security) pin is set, the lock should open. Once you've mastered the two pin lock and can distinguish reliably among pin states, you should have little trouble with a three pin lock. They have all kinds of very straight lines drawn across what is essentially an extremely wiggly-surfaced globe.